Misplaced Pages

#10989

161-695: Brachiosaurus is one of the best-known members of the Brachiosauridae, and was once thought to be the largest land animal to ever live. Brachiosaurids thrived in the regions which are now North and South America , Africa , Europe , and Asia . They first appear in the fossil record in the Late Jurassic Period (possibly even earlier in the Middle Jurassic) and disappear in the late Early Cretaceous Period . The broad distribution of Brachiosauridae in both northern and southern continents suggests that

322-399: A Meckelian groove that was open until below the ninth alveolus, continuing thereafter as a shallow trough. Each maxilla had space for fourteen or fifteen teeth, whereas Giraffatitan had eleven and Camarasaurus eight to ten. The maxillae contained replacement teeth that had rugose enamel , similar to Camarasaurus , but lacked the small denticles (serrations) along the edges. Since

483-462: A subadult , as indicated by the unfused suture between the coracoid , a bone of the shoulder girdle that forms part of the shoulder joint , and the scapula (shoulder blade). Over the years, the mass of the holotype specimen has been estimated within the range of 28.3–46.9 metric tons (31.2–51.7 short tons). Benson et al. suggested a maximum body mass of 56 and 58 metric tons (62 and 64 short tons), but these estimates were questioned due to

644-427: A syntype series, but in 1935 made S   I (presently MB.R.2180) the lectotype . Taylor in 2009, unaware of this action, proposed the larger and more complete S   II (MB.R.2181) as the lectotype. It includes, among other bones, several dorsal vertebrae, the left scapula, both coracoids, the breastbones , both humeri, both ulnae and radii (lower arm bones), a right hand, a partial left hand, both hip bones and

805-464: A brachiosaurid and named Vouivria damparisensis in 2017. This specimen represents the oldest undisputed record of the brachiosaurid group. The following diagram is a timeline of important brachiosaurid discoveries, the date given being that of the naming of the genus. The actual excavation was often much earlier, in the case of Vouivria eighty-three years and of Duriatitan at least 136 years. Definitive brachiosaurid remains have been found from

966-411: A broad, articular surface, which is divided into two parts by a slight ridge. Projecting on either side are the lateral and medial epicondyles . The articular surface extends a little lower than the epicondyles, and is curved slightly forward; its medial extremity occupies a lower level than the lateral. The lateral portion of this surface consists of a smooth, rounded eminence, named the capitulum of

1127-444: A cladistic analysis, finding them to be sister groups . Another 2010 analysis focusing on possible Asian brachiosaurid material found a clade including Abydosaurus , Brachiosaurus , Cedarosaurus , Giraffatitan , and Paluxysaurus , but not Qiaowanlong , the putative Asian brachiosaurid. Several subsequent analyses have found Brachiosaurus and Giraffatitan not to be sister groups, but instead located at different positions on

1288-581: A decrease in abundance of brachiosaurids acting in combination with the poor fossil record . Also, in 2017 a study indicated that Padillasaurus was not a brachiosaurid but a basal member of the Somphospondyli . Brachiosauridae is one of the two major clades of Titanosauriformes , a diverse group of sauropods that existed in the Late Jurassic and Cretaceous in Laurasia and Gondwana . Europasaurus

1449-425: A distinct tingling sensation, and sometimes a significant amount of pain. It is sometimes popularly referred to as 'the funny bone', possibly due to this sensation (a "funny" feeling), as well as the fact that the bone's name is a homophone of 'humorous'. It lies posterior to the medial epicondyle, and is easily damaged in elbow injuries. The deltoid originates on the lateral third of the clavicle , acromion and

1610-473: A gateway icon for the "DinoLand, U.S.A." area, known as the "Oldengate Bridge" that connects the two halves of the fossil quarry themed Boneyard play area. Further discoveries of Brachiosaurus material in North America have been uncommon and consist of a few bones. To date, material can be unambiguously ascribed only to the genus when overlapping with the holotype material, and any referrals of elements form

1771-520: A height of about fourteen meters. It has been argued that other sauropods lacked this dorsoventral flexibility and that their necks stretched outwards in front of them instead of upwards. Brachiosaurids have more often been found in the conifer-rich sites, like the Tendaguru , than in the Morrison deposits, suggesting that their fitness was increased by the presence of taller conifer food sources. However,

SECTION 10

#1732891890011

1932-1043: A large Cretaceous clade located mostly in Gondwana . Traditionally, Brachiosauridae included Brachiosaurus and some other suggestively assigned genera. Following the generic separation of Brachiosaurus species into B. altithorax and Giraffatitan brancai these have sometimes been the only members supported by cladistic analysis. Cladogram of Brachiosauridae after D'Emic et al. (2016). Europasaurus Giraffatitan Sonorasaurus Brachiosaurus Abydosaurus Cedarosaurus Venenosaurus Lusotitan Cladogram of Brachiosauridae after Mannion et al. (2017). Europasaurus Vouivria Brachiosaurus Giraffatitan Sonorasaurus Lusotitan Cedarosaurus Venenosaurus [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Brachiosaurus Brachiosaurus ( / ˌ b r æ k i ə ˈ s ɔː r ə s / )

2093-457: A larger difference than between Diplodocus and Barosaurus , and therefore argued that the African material should indeed be placed in its own genus ( Giraffatitan ) as Giraffatitan brancai . An important contrast between the two genera is their overall body shape, with Brachiosaurus having a 23 percent longer dorsal vertebral series and a 20 to 25 percent longer and also taller tail. The split

2254-469: A low bulge visible in side view, which is absent in Giraffatitan . Distinguishing features can also be found in the ilium of the pelvis. In Brachiosaurus , the ischiadic peduncle, a downward projecting extension connecting to the ischium , reaches farther downward than in Giraffatitan . While the latter genus had a sharp notch between the ischiadic peduncle and the back portion of the ilium, this notch

2415-417: A mid-dorsal vertebra, an incomplete left ilium, a left radius and a right metacarpal. According to Taylor in 2009, this specimen can be confidently referred to B. altithorax , as far as it is overlapping with its type specimen. Jensen further mentioned a specimen discovered near Jensen, Utah , that includes a rib 2.75 meters (9 ft 1 ⁄ 4  in) in length, an anterior cervical vertebra, part of

2576-528: A name for the new dinosaur. In 1903, he named the type species Brachiosaurus altithorax . Riggs derived the genus name from the Greek brachion /βραχίων meaning "arm" and sauros / σαυρος meaning "lizard", because he realized that the length of the arms was unusual for a sauropod. The specific epithet was chosen because of the unusually deep and wide chest cavity, from Latin altus "deep" and Greek thorax /θώραξ, "breastplate, cuirass, corslet". Latin thorax

2737-525: A nearly complete postcranial skeleton of a small juvenile approximately 2 meters (6 ft 7 in) in length. This specimen, nicknamed "Toni" and cataloged as SMA 0009, stems from the Morrison Formation of the Bighorn Basin in north-central Wyoming. Although originally thought to belong to a diplodocid , it was later reinterpreted as a brachiosaurid, probably belonging to B. altithorax . In 2018,

2898-399: A prominent bulge on the back side of the femoral shaft, was more prominent and located further downward. This bulge served as anchor point for the most important locomotory muscle, the caudofemoralis , which was situated in the tail and pulled the upper thigh backward when contracted. At the lower end of the femur, the pair of condyles did not extend backward as strongly as in Giraffatitan ;

3059-543: A proportionally taller neural arch, making the vertebra about thirty percent taller. The centrum lacked depressions on its sides, in contrast to Giraffatitan . In front or back view, the neural spine broadened toward its tip to approximately three times its minimum width, but no broadening is apparent in Giraffatitan . The neural spines were also inclined backward by about 30 degrees, more than in Giraffatitan (20 degrees). The caudal ribs projected laterally and were not tilted backward as in Giraffatitan . The articular facets of

3220-403: A sauropod and the metacarpal bones of the forelimb were elongated. These adaptations overall increased the stride length of the forelimbs, arguably resulting in an uneven gait. However, it was previously argued that they were hindlimb dominant like other sauropods, and thus had the ability to rear up on their hindlimbs. Based on the structure of their legs, making it impossible for them to run, it

3381-401: A scapula, and a coracoid, although he did not provide a description. In 2001, Curtice and Stadtman ascribed two articulated dorsal vertebrae (specimen BYU 13023) from Dry Mesa Quarry to Brachiosaurus . Taylor, in 2009, noted that these vertebrae are markedly shorter than those of the B. altithorax holotype, although otherwise being similar. In 2012, José Carballido and colleagues reported

SECTION 20

#1732891890011

3542-405: A shape which appears more pronounced by the frontal bones extending forward over the orbits (eye sockets). Similar to Giraffatitan , the neck of the occipital condyle was very long. The premaxilla appears to have been longer than that of Camarasaurus , sloping more gradually toward the nasal bar, which created the very long snout. Brachiosaurus had a long and deep maxilla (the main bone of

3703-443: A single line of neural spines on the back and had wide hips. Riggs considered the differences from other taxa significant enough to name a separate family, Brachiosauridae, of which Brachiosaurus is the namesake genus . According to Riggs, Haplocanthosaurus was the more primitive genus of the family while Brachiosaurus was a specialized form. When describing Brachiosaurus brancai and B. fraasi in 1914, Janensch observed that

3864-459: A species of Brachiosaurus , B. brancai , but moved to its own genus in 2009. Three other species of Brachiosaurus have been named based on fossils found in Africa and Europe ; two are no longer considered valid, and a third has become a separate genus, Lusotitan . The type specimen of B. altithorax is still the most complete specimen, and only a few other specimens are thought to belong to

4025-509: A steeply inclined trunk , and a proportionally shorter tail. Brachiosaurus is the namesake genus of the family Brachiosauridae , which includes a handful of other similar sauropods . Most popular depictions of Brachiosaurus are in fact based on Giraffatitan , a genus of brachiosaurid dinosaur from the Tendaguru Formation of Tanzania . Giraffatitan was originally described by German paleontologist Werner Janensch in 1914 as

4186-469: A study by R.F. Kingham, B. altithorax , B. brancai and B. atalaiensis , along with many species now assigned to other genera, were placed in the genus Astrodon , creating an Astrodon altithorax . Kingham's views of brachiosaurid taxonomy have not been accepted by many other authors. Since the 1990s, computer-based cladistic analyses allow for postulating detailed hypotheses on the relationships between species, by calculating those trees that require

4347-474: A subnarial fenestra, which was much larger than those of Giraffatitan and Camarasaurus . The dentaries (the bones of the lower jaws that contained the teeth) were robust, though less than in Camarasaurus . The upper margin of the dentary was arched in profile, but not as much as in Camarasaurus . The interdental plates of the dentary were somewhat oval, with diamond shaped openings between them. The dentary had

4508-406: A team and wagon to transport all fossils to the railway station, during five days; another week was spent to pack them in thirty-eight crates with a weight of 5,700 kilograms (12,500 lb). On September 10, Riggs left for Chicago by train, arriving on the 15th; the railroad companies let both passengers and cargo travel for free, as a public relations gesture. The holotype skeleton consists of

4669-472: A very large error range and lack of precision. The length of Brachiosaurus has been estimated at 20–22 meters (66–72   ft) and 18 meters (59 ft), and its height at 9.4 meters ( 30 + 3 ⁄ 4  ft) and 12–13 meters (39–43 ft). While the limb bones of the most complete Giraffatitan skeleton (MB.R.2181) were very similar in size to those of the Brachiosaurus type specimen,

4830-578: A water current. This is further evidenced by an isolated ilium of Diplodocus that apparently had drifted against the vertebral column, as well as by a change in composition of the surrounding rocks. While the specimen itself was embedded in fine-grained clay, indicating low-energy conditions at the time of deposition, it was cut off at the seventh presacral vertebra by a thick layer of much coarser sediments consisting of pebbles at its base and sandstone further up, indicating deposition under stronger currents. Based on this evidence, Riggs in 1904 suggested that

4991-578: Is a genus of sauropod dinosaur that lived in North America during the Late Jurassic , about 154   to 150   million years ago. It was first described by American paleontologist Elmer S. Riggs in 1903 from fossils found in the Colorado River valley in western Colorado , United States. Riggs named the dinosaur Brachiosaurus altithorax ; the generic name is Greek for "arm lizard", in reference to its proportionately long arms, and

Brachiosauridae - Misplaced Pages Continue

5152-617: Is a long bone in the arm that runs from the shoulder to the elbow . It connects the scapula and the two bones of the lower arm, the radius and ulna , and consists of three sections. The humeral upper extremity consists of a rounded head, a narrow neck, and two short processes ( tubercles , sometimes called tuberosities). The body is cylindrical in its upper portion, and more prismatic below. The lower extremity consists of 2 epicondyles , 2 processes ( trochlea and capitulum ), and 3 fossae ( radial fossa , coronoid fossa , and olecranon fossa ). As well as its true anatomical neck,

5313-605: Is a basal branch within the Titanosauriformes. The exact status of each potential brachiosaurid varies from study to study. For example, a 2010 study by Chure and colleagues recognized Abydosaurus as a brachiosaurid together with Brachiosaurus , which in this study included B. brancai . In 2009, Taylor noted multiple anatomical differences between the two Brachiosaurus species, and consequently moved B. brancai into its own genus, Giraffatitan . In contrast to earlier studies, Taylor treated both genera as distinct units in

5474-464: Is a brachiosaurid, which was confirmed by some later studies, such as an analysis in 2013. In 1958 French petroleum geologist F. Nougarède reported to have discovered fragmentary brachiosaurid remains in eastern Algeria , in the Sahara Desert . Based on these, Albert-Félix de Lapparent described and named the species Brachiosaurus nougaredi in 1960. He indicated the discovery locality as being in

5635-407: Is a rounded eminence forming the lateral part of the distal humerus. The head of the radius articulates with the capitulum. The trochlea is spool-shaped medial portion of the distal humerus and articulates with the ulna. The epicondyles are continuous above with the supracondylar ridges. The medial supracondylar crest forms the sharp medial border of the distal humerus continuing superiorly from

5796-410: Is considered the most basal brachiosaurid. Titanosauriformes was a globally distributed, long-lived clade of dinosaurs that contained both the largest and smallest known sauropods . This clade was composed of three distinct groups: Brachiosauridae, a mix of Late Jurassic and Early Cretaceous sauropods , Euhelopodidae , a group of mid- Cretaceous East Asian sauropods , and Titanosauria ,

5957-566: Is impossible to determine whether it belonged to the species B. altithorax itself (as there is no overlapping material between the two specimens). They based the skull's assignment to Brachiosaurus on its similarity to that of B. brancai , later known as Giraffatitan . In 2019, American paleontologists Michael D. D'Emic and Matthew T. Carrano re-examined the Felch Quarry skull after having it further prepared and CT-scanned (while consulting historical illustrations that showed earlier states of

6118-405: Is likely that they moved about in a low walking speed (20–40 km/day), but were capable of moving faster when necessary, up to 20–30 km/hour, depending on leg length. Brachiosaurids shared synapomorphies , new traits typical for the group. They possessed middle and rear back vertebrae with long, 'rod-like' transverse processes. In the pelvis, the ischium had a shortened pubic peduncle,

6279-444: Is located posteroinferior to the deltoid tuberosity. The inferior boundary of the spiral groove is continuous distally with the lateral border of the shaft. The nutrient foramen of the humerus is located in the anteromedial surface of the humerus. The nutrient arteries enter the humerus through this foramen. The distal or lower extremity of the humerus is flattened from before backward, and curved slightly forward; it ends below in

6440-478: Is more rounded in Brachiosaurus . On the upper surface of the hind part of the ilium, Brachiosaurus had a pronounced tubercle that is absent in other sauropods. Of the hindlimb, the femur was very similar to that of Giraffatitan although slightly more robust, and measured 203 centimeters (80 in) long. As in Giraffatitan , it was strongly elliptical in cross section, being more than twice as wide in front or back view than in side view. The fourth trochanter ,

6601-451: Is one of the specimens at the center of the Supersaurus / Ultrasauros issue of the 1980s and 1990s. In 1985 James A. Jensen described disarticulated sauropod remains from the quarry as belonging to several exceptionally large taxa , including the new genera Supersaurus and Ultrasaurus , the latter renamed Ultrasauros shortly thereafter because another sauropod had already received

Brachiosauridae - Misplaced Pages Continue

6762-568: Is one of the three main groups of the clade Titanosauriformes , which also includes the Euhelopodidae and the Titanosauria . The Brachiosauridae are composed of quadrupedal dinosaurs that are generally very large, with the exception of the possible insular dwarf Europasaurus . The brachiosaurids can be distinguished from other macronarian taxa by their broad, thick and spoon-shaped teeth. Their maxillary teeth were twisted apically, at

6923-426: Is placed laterally. The greater tubercle is where supraspinatus , infraspinatus and teres minor muscles are attached. The crest of the greater tubercle forms the lateral lip of the bicipital groove and is the site for insertion of pectoralis major . The greater tubercle is just lateral to the anatomical neck. Its upper surface is rounded and marked by three flat impressions: the highest of these gives insertion to

7084-403: Is slightly constricted and is termed the anatomical neck, in contradistinction to a constriction below the tubercles called the surgical neck which is frequently the seat of fracture. Fracture of the anatomical neck rarely occurs. The diameter of the humeral head is generally larger in men than in women. The anatomical neck ( collum anatomicum ) is obliquely directed, forming an obtuse angle with

7245-644: The Brushy Basin Member of the Morrison Formation , and therefore is late Kimmeridgian in age, about 154   to 153   million years old. Discovered by American paleontologist Elmer S. Riggs and his crew from the Field Columbian Museum (now the Field Museum of Natural History ) of Chicago , it is currently cataloged as FMNH   P   25107. Riggs and company were working in

7406-552: The Field Columbian Museum . Since then, the classification of these sauropods has been through many changes. Marsh's multifamily theory of sauropod classification prevailed until 1929, when Werner Janensch proposed a two-family theory based on differences in sauropod teeth. Macronarians with broad, spatulate teeth, were placed in the family Brachiosauridae, while sauropods with more slender and peg-shaped teeth were considered titanosaurs . This put diplodocids and titanosaurids together in one group based on their similar teeth, despite

7567-467: The Late Jurassic -age Taouratine Series. He assigned the rocks to this age in part because of the presumed presence of Brachiosaurus . A more recent review placed it in the " Continental intercalaire ", which is considered to belong to the Albian age of the late Early Cretaceous , significantly younger. The type material moved to Paris consisted of a sacrum, weathered out at the desert surface, and some of

7728-613: The Late Jurassic Period to the Early Cretaceous , from about 157 to 100 million years ago. In addition, Macronaria in general first appear in the Late Jurassic . However, the almost simultaneous appearance of Camarasaurus , Brachiosaurus , and a possible titanosaur suggest that they originated earlier, closer to the Mid-Jurassic. Trackway evidence also supports a Middle Jurassic origin for titanosaurs, which implies

7889-538: The Smithsonian Institution . Originally, this humerus was part of a poorly preserved partial skeleton that was not collected. According to Taylor in 2009, it is not clearly referable to Brachiosaurus despite its large size of 2.13 meters (6 ft 11 + 3 ⁄ 4  in). Jensen himself worked at the Potter Creek site in 1971 and 1975, excavating the disarticulated specimen BYU 4744, which contains

8050-570: The antorbital fenestra (the opening in front of the orbit), whereas they ended just in front of and below the fenestra in Camarasaurus and Shunosaurus . Riggs, in his preliminary 1903 description of the not yet fully prepared holotype specimen, considered Brachiosaurus to be an obvious member of the Sauropoda. To determine the validity of the genus, he compared it to the previously named genera Camarasaurus , Apatosaurus , Atlantosaurus , and Amphicoelias , whose validity he questioned given

8211-401: The entepicondylar foramen to allow the passage of nerves and blood vessels. During embryonic development, the humerus is one of the first structures to ossify, beginning with the first ossification center in the shaft of the bone. Ossification of the humerus occurs predictably in the embryo and fetus, and is therefore used as a fetal biometric measurement when determining gestational age of

SECTION 50

#1732891890011

8372-472: The intertubercular groove of the humerus. They work to adduct and medially, or internally, rotate the humerus. The infraspinatus and teres minor insert on the greater tubercle, and work to laterally, or externally, rotate the humerus. In contrast, the subscapularis muscle inserts onto the lesser tubercle and works to medially, or internally, rotate the humerus. The biceps brachii , brachialis , and brachioradialis (which attaches distally) act to flex

8533-467: The neural arch of the vertebrae) were horizontal, while those of Giraffatitan were inclined upward. At their ends, these projections articulated with the ribs; the articular surface was not distinctly triangular as in Giraffatitan . In side view, the upward-projecting neural spines stood vertically and were twice as wide at the base than at the top; those of Giraffatitan tilted backward and did not broaden at their base. When seen in front or back view,

8694-448: The specific name means "deep chest". Brachiosaurus is estimated to have been between 18 and 22 meters (59 and 72 ft) long; body mass estimates of the subadult holotype specimen range from 28.3 to 46.9 metric tons (31.2 to 51.7 short tons). It had a disproportionately long neck, small skull, and large overall size, all of which are typical for sauropods. Atypically, Brachiosaurus had longer forelimbs than hindlimbs, which resulted in

8855-400: The supraspinatus muscle ; the middle to the infraspinatus muscle ; the lowest one, and the body of the bone for about 2.5 cm. below it, to the teres minor muscle . The lateral surface of the greater tubercle is convex, rough, and continuous with the lateral surface of the body. The lesser tubercle ( tuberculum minus ; lesser tuberosity) is smaller, anterolaterally placed to the head of

9016-458: The vertebrae and ribs by bone resorption , greatly reducing the overall density of the body. The neck is not preserved in the holotype specimen , but was very long even by sauropod standards in the closely related Giraffatitan , consisting of thirteen elongated cervical (neck) vertebrae. The neck was held in a slight S-curve, with the lower and upper sections bent and a straight middle section. Brachiosaurus likely shared with Giraffatitan

9177-411: The African material, but vary widely in B. altithorax . Paul believed that the limb and girdle elements of both species were very similar, and therefore suggested they be separated not at genus, but only at subgenus level, as Brachiosaurus (Brachiosaurus) altithorax and Brachiosaurus (Giraffatitan) brancai . Giraffatitan was raised to full genus level by George Olshevsky in 1991, while referring to

9338-507: The Brachiosauridae, and the rest are either difficult to assess or refer to material that is not Brachiosaurus . There was ample material referred to B. brancai in the collections of the Museum für Naturkunde in Berlin, some of which was destroyed during World War II . Other material was transferred to other institutions throughout Germany, some of which was also destroyed. Additional material

9499-603: The Early Cretaceous seems to be a time of reduced sauropod diversity worldwide. It has been argued that this change may be due to an extinction event at the Jurassic-Cretaceous boundary. A second hypothesis is that the apparent lack of geographical diversity is due to sampling bias in the generally poor Early Cretaceous fossil record. Recently discovered evidence supports the conclusion that brachiosaurids existed outside of North America in lower latitudes of Gondwana in

9660-601: The Early Cretaceous. In 2013, Mannion et al. reported on the discovery of two isolated teeth found in Lebanon from the Early Cretaceous that possess posteriorly twisted crowns, which are characteristic of the brachiosaurids Giraffatitan and Abydosaurus . In addition, a brachiosaurid named Padillasaurus leivaensis was discovered in Colombia from the Early Cretaceous and placed in the Brachiosauridae taxon , which suggests that Brachiosauridae survived in northwestern Gondwana after

9821-564: The Felch quarry skull and another Camarasaurus -like skull to Brontosaurus , it would have been recognized earlier that the actual skull of Brontosaurus and Apatosaurus was more similar to that of Diplodocus . McIntosh later tentatively recognized the Felch Quarry skull as belonging to Brachiosaurus , and brought it to the attention of the American paleontologists Kenneth Carpenter and Virginia Tidwell, while urging them to describe it. They brought

SECTION 60

#1732891890011

9982-506: The Field Museum's newly mounted Apatosaurus was unveiled, the very specimen Riggs had found in Quarry 12, today catalogued as FMNH P25112 and identified as a Brontosaurus exemplar. No mount of Brachiosaurus was attempted because only twenty percent of the skeleton had been recovered. In 1993, the holotype bones were molded and cast, and the missing bones were sculpted based on material of

10143-620: The Field Museum. First the limb elements were processed. In the winter of 1904, the badly weathered vertebrae of the back and hip were prepared by James B. Abbott and C.T. Kline. As the preparation of each bone was finished, it was put on display in a glass case in Hall 35 of the Fine Arts Palace of the Worlds Columbian Exposition , the Field Museum's first location. All the bones were, solitarily, still on display by 1908 in Hall 35 when

10304-499: The Jurassic/Cretaceous boundary. In the Early Cretaceous, Colombia was located close to the equator in northwestern Gondwana while Lebanon was in the northeast of Gondwana. This suggests that brachiosaurids were in fact present outside of North America in the Early Cretaceous, and supports the theory that the apparent lack of specimens is due to an incomplete record. However, the rarity of these dinosaur specimens may also reflect

10465-595: The Late Jurassic, their geographic distribution narrowed in the Early Cretaceous. So far, brachiosaurid specimens have only been found in the Aptian-Albian region of North America. This reduction in distribution occurs immediately following the Jurassic-Cretaceous boundary. The brachiosaurid distribution in the Early Cretaceous has been interpreted as a result of regional extinctions in Europe, Africa, and South America. Overall,

10626-401: The Titanosauriformes as a whole. They concluded that the family Brachiosauridae was actually a "grade" of not specially related primitive titanosauriforms, and not a stable separate clade . They partly based this conclusion on similar humerus:femur length ratios known for titanosauriforms, basal titanosaurs, and more basal sauropods. However, in 1998 Sereno & Wilson published data contrary to

10787-504: The Western Colorado Academy of Science, that dinosaur bones had been collected near Grand Junction since 1885. Riggs was skeptical of this claim, but his superior, curator of geology Oliver Cummings Farrington, was very eager to add a large sauropod skeleton to the collection to outdo other institutions, and convinced the museum management to invest five hundred dollars in an expedition. Arriving on June 20, 1900, they set camp at

10948-437: The abandoned Goat Ranch. During a prospecting trip on horseback, Riggs's field assistant Harold William Menke found the humerus of FMNH   P   25107, on July 4, exclaiming it was "the biggest thing yet!". Riggs at first took the find for a badly preserved Brontosaurus specimen and gave priority to excavating Quarry 12, which held a more promising Morosaurus skeleton. Having secured that, on July 26 he returned to

11109-401: The actions of lifting/pulling and pressing/pushing. Primitive fossils of amphibians had little, if any, shaft connecting the upper and lower extremities, making their limbs very short. In most living tetrapods , however, the humerus has a similar form to that of humans. In many reptiles and some mammals (where it is the primitive state), the lower extremity includes a large opening called

11270-415: The anterior border of the head of the radius, when the forearm is flexed. These fossæ are separated from one another by a thin, transparent lamina of bone, which is sometimes perforated by a supratrochlear foramen ; they are lined in the fresh state by the synovial membrane of the elbow-joint , and their margins afford attachment to the anterior and posterior ligaments of this articulation. The capitulum

11431-439: The area as a result of favorable correspondence between Riggs and Stanton Merill Bradbury, a dentist in nearby Grand Junction . In the spring of 1899 Riggs had sent letters to mayors in western Colorado , inquiring after possible trails leading from railway heads into northeastern Utah , where he hoped to find fossils of Eocene mammals . To his surprise, he was informed by Bradbury, an amateur collector himself and president of

11592-423: The arms of Brachiosaurus appear to have been slightly sprawled at the shoulder joints, as indicated by the sideward orientation of the joint surfaces of the coracoids. The humerus was less slender than that of Giraffatitan , while the femur had similar proportions. This might indicate that the forelimbs of Brachiosaurus supported a greater fraction of the body weight than is the case for Giraffatitan . Though

11753-400: The articular processes at the back of the vertebra were directed downward, while those of Giraffatitan faced more toward the sides. Besides the articular processes, the hyposphene-hypantrum articulation formed an additional articulation between vertebrae, making the vertebral column more rigid; in Brachiosaurus , the hyposphene was much more pronounced than in Giraffatitan . The coracoid

11914-400: The back side of the neural spines. The spinodiapophyseal laminae, which stretched from the neural spines to the diapophyses, were conflated with the spinopostzygapophyseal laminae, which stretched between the neural spines and the articular processes at the back of the vertebrae, and therefore terminated at mid-height of the neural spines. In Giraffatitan , both laminae were not conflated, and

12075-449: The body. It is best marked in the lower half of its circumference; in the upper half it is represented by a narrow groove separating the head from the tubercles. The line separating the head from the rest of the upper end is called the anatomical neck. It affords attachment to the articular capsule of the shoulder-joint, and is perforated by numerous vascular foramens . Fracture of the anatomical neck rarely occurs. The anatomical neck of

12236-631: The bone it was found on, but did state that "general similarities" with Sonorasaurus and Giraffatitan suggested brachiosaurid affinities, but this, the authors stated, would be confirmed only through further study. Between 1909 and 1912, large-scale paleontological expeditions in German East Africa unearthed a considerable amount of brachiosaurid material from the Tendaguru Formation . In 1914, German paleontologist Werner Janensch listed differences and commonalities between these fossils and B. altithorax , concluding they could be referred to

12397-473: The bones), and concluded that a quadrate bone and dentary tooth considered part of the skull by Carpenter and Tidwell did not belong to it. The quadrate is too large to articulate with the squamosal, is preserved differently from the other bones, and was found several meters away. The tooth does not resemble those within the jaws (as revealed by CT data), is larger, and was therefore assigned to Camarasaurus sp. (other teeth assignable to that genus are known from

12558-400: The characteristic long necks of brachiosaurids are distinct from those of other long-necked dinosaur taxa . They possessed a narrow neck composed of twelve to thirteen extremely long cervical vertebrae that was laterally inflexible and dorsoventrally, vertically, flexible. This meant that brachiosaurids could angle their necks up and lift their heads, enabling them to graze from treetops up to

12719-407: The closely related Giraffatitan . The trunk was about 25 to 30 percent longer, resulting in a dorsal vertebral column longer than the humerus. Only a single complete caudal (tail) vertebra has been discovered, but its great height suggests that the tail was larger than in Giraffatitan . This vertebra had a much greater area for ligament attachment due to a broadened neural spine , indicating that

12880-532: The conclusions in Salgado et al.'s article, indicating that the Brachiosauridae were a separate clade in the Titanosauriformes. After 1998, new brachiosaurid species have been named, generally confirming that the Brachiosauridae were a natural group. In 1943, de Lapparent described the "French Bothriospondylus" from the Oxfordian of France which dates to the Late Jurassic , which was identified in 2013 by Philip Mannion as

13041-429: The constriction below the greater and lesser tubercles of the humerus is referred to as its surgical neck due to its tendency to fracture, thus often becoming the focus of surgeons. The word "humerus" is derived from Late Latin humerus , from Latin umerus , meaning upper arm, shoulder, and is linguistically related to Gothic ams (shoulder) and Greek ōmos . The upper or proximal extremity of

13202-408: The contact surface with the pubic bone . Their humeri , upper arm bones, had a large deltopectoral crest . Their skull roofs showed wide supratemporal fenestrae, openings for the muscles. They had neural arches placed more on front of the vertebrae, shoulder blades that were expanded at the top end, irregularly shaped coracoids in the shoulder girdle, and triangular projections on the underside of

13363-521: The cranium, the maxillae, the right postorbital, part of the left maxilla, the left squamosal , the dentaries, and a possible partial pterygoid . The bones were roughly prepared for Marsh, which led to some damage. Felch also collected several postcranial fossils, including a partial cervical vertebra and partial forelimb. Most of the specimens collected by Felch were sent to the National Museum of Natural History in 1899 after Marsh's death, including

13524-421: The crest of the spine of the scapula. It is inserted on the deltoid tuberosity of the humerus and has several actions including abduction, extension, and circumduction of the shoulder. The supraspinatus also originates on the spine of the scapula. It inserts on the greater tubercle of the humerus, and assists in abduction of the shoulder. The pectoralis major , teres major , and latissimus dorsi insert at

13685-433: The elbow. (The biceps do not attach to the humerus.) The triceps brachii and anconeus extend the elbow, and attach to the posterior side of the humerus. The four muscles of supraspinatus, infraspinatus, teres minor and subscapularis form a musculo-ligamentous girdle called the rotator cuff . This cuff stabilizes the very mobile but inherently unstable glenohumeral joint . The other muscles are used as counterbalances for

13846-485: The elongated forearm and metacarpus of other brachiosaurids. This resulted in an inclined trunk with the shoulder much higher than the hips, and the neck exiting the trunk at a steep angle. The overall build of Brachiosaurus resembles a giraffe more than any other living animal. In contrast, most other sauropods had a shorter forelimb than hindlimb; the forelimb is especially short in contemporaneous diplodocoids . Brachiosaurus differed in its body proportions from

14007-455: The evolutionary tree. A 2012 study by D'Emic placed Giraffatitan in a more basal position, in an earlier branch, than Brachiosaurus , while a 2013 study by Philip Mannion and colleagues had it the other way around. This cladogram follows that published by Michael D. D'Emic in 2012: Europasaurus Giraffatitan Brachiosaurus Abydosaurus Humeri The humerus ( / ˈ h juː m ər ə s / ; pl. : humeri )

14168-415: The extremity. The grooved portion of the articular surface fits accurately within the semilunar notch of the ulna; it is broader and deeper on the posterior than on the anterior aspect of the bone, and is inclined obliquely downward and forward toward the medial side. At the shoulder, the head of the humerus articulates with the glenoid fossa of the scapula . More distally, at the elbow, the capitulum of

14329-407: The family Bothrosauropodidae. During the twentieth century, several sauropods were assigned to Brachiosauridae, including Astrodon , Bothriospondylus , Pelorosaurus , Pleurocoelus , and Ultrasauros . These assignments were often based on broad similarities rather than unambiguous synapomorphies , shared new traits, and most of these genera are currently regarded as dubious . In 1969, in

14490-409: The fewest evolutionary changes and thus are the most likely to be correct. Such cladistic analyses have cast doubt on the validity of the Brachiosauridae. In 1993, Leonardo Salgado suggested that they were an unnatural group into which all kinds of unrelated sauropods had been combined. In 1997, he published an analysis in which species traditionally considered brachiosaurids were subsequent offshoots of

14651-472: The former was somewhat lighter than the Brachiosaurus specimen given its proportional differences. In studies including estimates for both genera, Giraffatitan was estimated at 31.5 metric tons (34.7 short tons), 39.5 metric tons (43.5 short tons), 38.0 metric tons (41.9 short tons), 23.3 metric tons (25.7 short tons), and 34.0 metric tons (37.5 short tons). As with the main Brachiosaurus specimen, Giraffatitan specimen MB.R.2181 likely does not reflect

14812-465: The front and back sides of the tuberculum, a bony projection articulating with the diapophyses of the vertebrae. Paul, in 1988, stated that the ribs of Brachiosaurus were longer than in Giraffatitan , which was questioned by Taylor in 2009. Behind the dorsal vertebral column, the sacrum consisted of five co- ossified sacral vertebrae . As in Giraffatitan , the sacrum was proportionally broad and featured very short neural spines. Poor preservation of

14973-401: The front branch of their quadratojugal bones at the lower rear corner of the skull. In 1903, Elmer Samuel Riggs described and named Brachiosaurus . In 1904, he created a new sauropod family, the Brachiosauridae. He published a complete description of the phenotype after examining the humerus , femur , coracoid , and sacrum of the Brachiosaurus holotype that had been prepared at

15134-563: The genus Brachiosaurus . From this material Janensch named two species: Brachiosaurus brancai for the larger and more complete taxon, and Brachiosaurus fraasi for the smaller and more poorly known species. In three further publications in 1929, 1950 and 1961, Janensch compared the species in more detail, listing thirteen shared characters between Brachiosaurus brancai (which he now considered to include B. fraasi ) and B. altithorax . Taylor, in 2009, considered only four of these characters as valid; six pertain to groups more inclusive than

15295-466: The genus, making it one of the rarer sauropods of the Morrison Formation . It is regarded as a high browser , possibly cropping or nipping vegetation as high as 9 meters (30 ft) off the ground. Unlike other sauropods, it was unsuited for rearing on its hindlimbs. It has been used as an example of a dinosaur that was most likely ectothermic because of its large size and the corresponding need for sufficient forage , but more recent research suggests it

15456-466: The giant size and long necks of brachiosaurids meant that they required tremendous pressure to bring oxygenated blood to their brains. It has been proposed that sauropods possessed a four-chambered double pump heart, with one pump for oxygenated and one pump for deoxygenated blood. As in all Macronaria , the forelimbs of brachiosaurids are long relative to the hindlimbs, but this trait is more pronounced in brachiosaurids. The forelimbs were very slender for

15617-619: The global spread present in the Late Jurassic. This conclusion is further supported by paleogeographic data. While many Late Jurassic dinosaur remains have been found in China , no brachiosaurid remains have been uncovered in East Asia. This would support the Middle Jurassic origin theory since East Asia was separated from the rest of Pangaea by water from the late Middle Jurassic to the Early Cretaceous. While brachiosaurids were widely dispersed in

15778-407: The group originated prior to the breakup of Pangaea . In the Early Cretaceous the distribution of the group is dramatically reduced. It is still unclear whether this reduction is due to local extinctions or to the limited nature of the Early Cretaceous fossil record. Brachiosauridae has been defined as all titanosauriforms that are more closely related to Brachiosaurus than to Saltasaurus . It

15939-439: The humerus consists of the bone's large rounded head joined to the body by a constricted portion called the neck, and two eminences, the greater and lesser tubercles. The head ( caput humeri ), is nearly hemispherical in form. It is directed upward, medialward, and a little backward, and articulates with the glenoid cavity of the scapula to form the glenohumeral joint (shoulder joint) . The circumference of its articular surface

16100-412: The humerus ; it articulates with the cup-shaped depression on the head of the radius, and is limited to the front and lower part of the bone. Above the front part of the trochlea is a small depression, the coronoid fossa , which receives the coronoid process of the ulna during flexion of the forearm. Above the back part of the trochlea is a deep triangular depression, the olecranon fossa , in which

16261-404: The humerus articulates with the head of the radius , and the trochlea of the humerus articulates with the trochlear notch of the ulna . The axillary nerve is located at the proximal end, against the shoulder girdle. Dislocation of the humerus's glenohumeral joint has the potential to injure the axillary nerve or the axillary artery . Signs and symptoms of this dislocation include a loss of

16422-400: The humerus in Quarry 13, which soon proved to be of enormous size, convincing a puzzled Riggs that he had discovered the largest land animal ever. The site, Riggs Quarry 13, is located on a small hill later known as Riggs Hill; it is today marked by a plaque. More Brachiosaurus fossils are reported on Riggs Hill, but other fossil finds on the hill have been vandalized. During excavation of

16583-402: The humerus is an indentation distal to the head of the humerus on which the articular capsule attaches. The surgical neck is a narrow area distal to the tubercles that is a common site of fracture. It makes contact with the axillary nerve and the posterior humeral circumflex artery . The greater tubercle ( tuberculum majus ; greater tuberosity) is a large, posteriorly placed projection that

16744-476: The humerus. The lesser tubercle provides insertion to subscapularis muscle. Both these tubercles are found in the proximal part of the shaft. The crest of the lesser tubercle forms the medial lip of the bicipital groove and is the site for insertion of teres major and latissimus dorsi muscles. The lesser tuberosity, is more prominent than the greater: it is situated in front, and is directed medialward and forward. Above and in front it presents an impression for

16905-413: The insertion of the tendon of the subscapularis muscle . The tubercles are separated from each other by a deep groove, the bicipital groove (intertubercular groove; bicipital sulcus), which lodges the long tendon of the biceps brachii muscle and transmits a branch of the anterior humeral circumflex artery to the shoulder-joint. It runs obliquely downward, and ends near the junction of the upper with

17066-465: The lack of overlapping fossil material. Because of the uncertain relationships of these genera, little could be said about the relationships of Brachiosaurus itself. In 1904, Riggs described the holotype material of Brachiosaurus in more detail, especially the vertebrae. He admitted that he originally had assumed a close affinity with Camarasaurus , but now decided that Brachiosaurus was more closely related to Haplocanthosaurus . Both genera shared

17227-478: The largest sauropod foot ever found was reported from the Black Hills of Weston County , Wyoming. The femur is not preserved but comparisons suggest that it was about two percent longer than that of the B. altithorax holotype. Though possibly belonging to Brachiosaurus , the authors cautiously classified it as an indeterminate brachiosaurid. However, the assignment of these two specimens to their respective clades

17388-436: The lectotype; this specimen includes twenty-eight vertebrae, chevrons , ribs, a possible shoulder blade, humeri, forearm bones, partial left pelvis, lower leg bones, and part of the right ankle. The low neural spines, the prominent deltopectoral crest of the humerus (a muscle attachment site on the upper arm bone), the elongated humerus (very long and slender), and the long axis of the ilium tilting upward indicate that Lusotitan

17549-554: The left metacarpals and phalanges . Found at the discovery site but not collected, were partial bones of the left forearm, wrist bones, a right shin bone, and fragments that may have come from metatarsals . B. nougaredi was in 2004 considered to represent a distinct, unnamed brachiosaurid genus, but a 2013 analysis by Philip D. Mannion and colleagues found that the remains possibly belong to more than one species, as they were collected far apart. The metacarpals were concluded to belong to some indeterminate titanosauriform . The sacrum

17710-434: The lower end of the humerus, the underside of the sacrum, the ilium and the preserved caudal vertebrae were exposed to the air and thus partly damaged by weathering. The vertebrae were only slightly shifted out of their original anatomical position; they were found with their top sides directed downward. The ribs, humerus, and coracoid, however, were displaced to the left side of the vertebral column, indicating transportation by

17871-533: The many other differences between the taxa . Today, about four to five groups within the Macronaria are considered families (with names ending in ~idae). In 1997, Salgado, Coria and Calvo studied the traits that had been used to set the Brachiosauridae apart and determined that they were in fact plesiomorphic , original, for all basal Titanosauriformes . They proposed that some characteristics that had been used to differentiate Brachiosaurus were synapomorphies for

18032-424: The maxilla was wider than that of Camarasaurus , Brachiosaurus would have had larger teeth. The replacement teeth in the premaxilla had crinkled enamel, and the most complete of these teeth did not have denticles. It was somewhat spatulate (spoon-shaped), and had a longitudinal ridge. Each dentary had space for about fourteen teeth. The maxillary tooth rows of Brachiosaurus and Giraffatitan ended well in front of

18193-415: The maximum size of the genus, as a fibula (specimen HM   XV2) is thirteen percent longer than that of MB.R.2181. Like all sauropod dinosaurs, Brachiosaurus was a quadruped with a small skull, a long neck, a large trunk with a high- ellipsoid cross section, a long, muscular tail and slender, columnar limbs. Large air sacs connected to the lung system were present in the neck and trunk, invading

18354-413: The medial epicondyle. The lateral supracondylar crest forms the sharp lateral border of the distal humerus continuing superiorly from the lateral epicondyle. The medial portion of the articular surface is named the trochlea , and presents a deep depression between two well-marked borders; it is convex from before backward, concave from side to side, and occupies the anterior, lower, and posterior parts of

18515-461: The middle third of the bone. In the fresh state its upper part is covered with a thin layer of cartilage, lined by a prolongation of the synovial membrane of the shoulder-joint; its lower portion gives insertion to the tendon of the latissimus dorsi muscle . It is deep and narrow above, and becomes shallow and a little broader as it descends. Its lips are called, respectively, the crests of the greater and lesser tubercles ( bicipital ridges ), and form

18676-412: The missing front part of the skeleton was washed away by a water current, while the hind part was already covered by sediment and thus got preserved. Riggs published a short report of the new find in 1901, noting the unusual length of the humerus compared to the femur and the extreme overall size and the resulting giraffe-like proportions, as well as the lesser development of the tail, but did not publish

18837-583: The name. Later study showed that the "ultrasaur" material mostly belonged to Supersaurus , though the shoulder blade did not. Because the holotype of Ultrasauros , a dorsal vertebra, was one of the specimens that was actually from Supersaurus , the name Ultrasauros is a synonym of Supersaurus . The shoulder blade, specimen BYU 9462 (previously BYU 5001), was in 1996 assigned to a Brachiosaurus sp. (of uncertain species) by Brian Curtice and colleagues; in 2009 Michael P. Taylor concluded that it could not be referred to B. altithorax . The Dry Mesa "ultrasaur"

18998-590: The neural spines widened toward their tops. In Brachiosaurus , this widening occurred gradually, resulting in a paddle-like shape, while in Giraffatitan the widening occurred abruptly and only in the uppermost portion. At both their front and back sides, the neural spines featured large, triangular and rugose surfaces, which in Giraffatitan were semicircular and much smaller. The various vertebral processes were connected by thin sheets or ridges of bone, which are called laminae . Brachiosaurus lacked postspinal laminae, which were present in Giraffatitan , running down

19159-434: The normal shoulder contour and a palpable depression under the acromion. The radial nerve follows the humerus closely. At the midshaft of the humerus, the radial nerve travels from the posterior to the anterior aspect of the bone in the spiral groove . A fracture of the humerus in this region can result in radial nerve injury. The ulnar nerve lies at the distal end of the humerus near the elbow. When struck, it can cause

19320-447: The nostrils, typical of brachiosaurids. The snout was somewhat blunt when seen from above (as in Giraffatitan ), and since it was set at an angle relative to the rest of the skull, gave the impression of pointing downward. The dorsal and lateral temporal fenestrae (openings at the upper rear and sides of the skull) were large, perhaps due to the force imparted there by the massive jaw adductor musculature. The frontal bones on top of

19481-429: The publication of the 2004 book, the species had been placed in its own genus Lusotitan by Miguel Telles Antunes and Octávio Mateus in 2003. De Lapparent and Zbyszewski had described a series of remains but did not designate a type specimen . Antunes and Mateus selected a partial postcranial skeleton ( MIGM   4978, 4798, 4801–4810, 4938, 4944, 4950, 4952, 4958, 4964–4966, 4981–4982, 4985, 8807, 8793–87934) as

19642-400: The quarry). They also found it most parsimonious to assign the skull to B. altithorax itself rather than an unspecified species, as there is no evidence of other brachiosaurid taxa in the Morrison Formation (and adding this and other possible elements to a phylogenetic analysis did not change the position of B. altithorax ). A shoulder blade with coracoid from Dry Mesa Quarry , Colorado,

19803-454: The related Brachiosaurus brancai (now Giraffatitan ) in Museum für Naturkunde , Berlin. This plastic skeleton was mounted and, in 1994, put on display at the north end of Stanley Field Hall, the main exhibit hall of the Field Museum's current building. The real bones of the holotype were put on exhibit in two large glass cases at either end of the mounted cast. The mount stood until 1999, when it

19964-472: The related brachiosaurid Giraffatitan (formerly known as B. brancai ), which is known from much more complete material than Brachiosaurus . The two species are the largest brachiosaurids of which relatively extensive remains have been discovered. There is another element of uncertainty for the North American Brachiosaurus because the type (and most complete) specimen appears to represent

20125-440: The right femur, tibia and fibula (shank bones). Later in 2011, Taylor realized that Janensch had designated the smaller skeleton S   I as the lectotype in 1935. In 1988 Gregory S. Paul published a new reconstruction of the skeleton of B. brancai , highlighting differences in proportion between it and B. altithorax . Chief among them was a distinction in the way the trunk vertebrae vary: they are fairly uniform in length in

20286-403: The right humerus (upper arm bone), the right femur (thigh bone), the right ilium (a hip bone), the right coracoid (a shoulder bone), the sacrum (fused vertebrae of the hip), the last seven thoracic (trunk) and two caudal (tail) vertebrae, and several ribs. Riggs described the coracoid as from the left side of the body, but restudy has shown it to be a right coracoid. At the time of discovery,

20447-432: The sacral material in Giraffatitan precludes detailed comparisons between both genera. Of the tail, only the second caudal vertebra is well preserved. As in Giraffatitan , this vertebra was slightly amphicoelous (concave on both ends), lacked openings on the sides, and had a short neural spine that was rectangular and tilted backward. In contrast to the second caudal vertebra of Giraffatitan , that of Brachiosaurus had

20608-497: The same for all neosauropods . Brachiosaurids in particular have a broad distribution dating to the Late Jurassic . Late Jurassic specimens have been discovered in the northern and southern Hemispheres, including North America , Africa , Europe , and South America . This suggests that brachiosaurids originated in the Middle Jurassic , prior to the breakup of Pangaea , followed by diversification and dispersal that resulted in

20769-403: The shaft has a crest, beginning just below the surgical neck of the humerus and extends till the superior tip of the deltoid tuberosity. This is where the lateral head of triceps brachii is attached. The radial sulcus, also known as the spiral groove is found on the posterior surface of the shaft and is a shallow oblique groove through which the radial nerve passes along with deep vessels. This

20930-419: The skull to have been 70 centimeters ( 27 + 1 ⁄ 2  in) long, and if proportionally similar to that of Giraffatitan , about 55 centimeters ( 21 + 1 ⁄ 2  in) tall, and 35 centimeters (14 in) wide. Overall, the skull was tall as in Giraffatitan , with a snout that was long (about 36 percent of the skull length according to Carpenter and Tidwell) in front of the nasal bar between

21091-456: The skull to the Denver Museum of Natural History , where they further prepared it and made a reconstruction of it based on casts of the individual bones, with the skulls of Giraffatitan and Camarasaurus acting as templates for the missing bones. In 1998 Carpenter and Tidwell described the Felch Quarry skull, and formally assigned it to Brachiosaurus sp. (of uncertain species), since it

21252-411: The skull were short and wide (similar to Giraffatitan ), fused and connected by a suture to the parietal bones , which were also fused together. The surface of the parietals between the dorsal fenestrae was wider than that of Giraffatitan , but narrower than that of Camarasaurus . The skull differed from that of Giraffatitan in its U-shaped (instead of W-shaped) suture between frontal and nasal bones,

21413-471: The skull, neck, anterior dorsal region, or distal limbs or feet remain tentative. Nevertheless, material has been described from Colorado, Oklahoma, Utah, and Wyoming, and undescribed material has been mentioned from several other sites. In 1883, farmer Marshall Parker Felch, a fossil collector for the American paleontologist Othniel Charles Marsh , reported the discovery of a sauropod skull in Felch Quarry 1, near Garden Park, Colorado . The skull

21574-501: The skull, which was then cataloged as USNM 5730. In 1975 the American paleontologists Jack McIntosh and David Berman investigated the historical issue of whether Marsh had assigned an incorrect skull to Brontosaurus (at the time thought to be a junior synonym of Apatosaurus ), and found the Felch Quarry skull to be of "the general Camarasaurus type", while suggesting that the vertebra found near it belonged to Brachiosaurus . They concluded that if Marsh had not arbitrarily assigned

21735-402: The specimen, Riggs misidentified the humerus as a deformed femur due to its great length, and this seemed to be confirmed when an equally-sized, well-preserved real femur of the same skeleton was discovered. In 1904 Riggs noted: "Had it not been for the unusual size of the ribs found associated with it, the specimen would have been discarded as an Apatosaur, too poorly preserved to be of value." It

21896-453: The spinodiapophyseal laminae reached up to the top of the neural spines. Brachiosaurus is further distinguished from Giraffatitan in lacking three details in the laminae of the dorsal vertebrae that are unique to the latter genus. Air sacs not only invaded the vertebrae but also the ribs. In Brachiosaurus , the air sacs invaded through a small opening on the front side of the rib shafts, while in Giraffatitan openings were present on both

22057-467: The stem of a larger grouping, the Titanosauriformes , and not a separate branch of their own. This study also pointed out that B. altithorax and B. brancai did not have any synapomorphies, so that there was no evidence to assume they were particularly closely related. Many cladistic analyses have since suggested that at least some genera can be assigned to the Brachiosauridae, and that this group

22218-405: The summit of the olecranon is received in extension of the forearm. The coronoid fossa is the medial hollow part on the anterior surface of the distal humerus. The coronoid fossa is smaller than the olecranon fossa and receives the coronoid process of the ulna during maximum flexion of the elbow. Above the front part of the capitulum is a slight depression, the radial fossa , which receives

22379-435: The tail was also longer than in Giraffatitan , possibly by 20 to 25 percent. In 1988, paleontologist Gregory S. Paul suggested that the neck of Brachiosaurus was shorter than that of Giraffatitan , but in 2009, paleontologist Mike P. Taylor pointed out that two cervical vertebrae likely belonging to Brachiosaurus had identical proportions. Unlike Giraffatitan and other sauropods, which had vertically oriented forelimbs,

22540-408: The third and fifth dorsal (back) vertebra, where the sideward- and upward-directed vertebral processes were longer, providing additional surface for neck muscle attachment. The ribcage was deep compared to other sauropods. Though the humerus (upper arm bone) and femur (thigh bone) were roughly equal in length, the entire forelimb would have been longer than the hindlimb, as can be inferred from

22701-458: The top, and the shape of these teeth was optimal for biting off resistant vegetation. While brachiosaurids, like other sauropods, did not perform significant food processing in their mouths, their teeth enabled them to slice through food instead of having to pull it from tree branches. Evidence for this precision shearing consists of apical wear facets on the teeth and distinctive bone structure that suggests orthal, vertical, jaw action. In addition,

22862-439: The two condyles were similar in width in Brachiosaurus but unequal in Giraffatitan . As reconstructed by Carpenter and Tidwell, the assigned Felch Quarry skull was about 81 centimeters (32 in) long from the occipital condyle at the back of the skull to the front of the premaxillae (the front bones of the upper jaw), making it the largest sauropod skull from the Morrison Formation . D'Emic and Carrano instead estimated

23023-522: The unique elongation of the humerus was shared by all three Brachiosaurus species as well as the British Pelorosaurus . He also noted this feature in Cetiosaurus , where it was not as strongly pronounced as in Brachiosaurus and Pelorosaurus . Janensch concluded that the four genera must have been closely related to each other, and in 1929 assigned them to a subfamily Brachiosaurinae within

23184-458: The upper jaw), which was thick along the margin where the alveoli (tooth sockets) were placed, thinning upward. The interdental plates of the maxilla were thin, fused, porous, and triangular. There were triangular nutrient foramina between the plates, each containing the tip of an erupting tooth . The narial fossa (depression) in front of the bony nostril was long, relatively shallow, and less developed than that of Giraffatitan . It contained

23345-434: The upper parts of the anterior and medial borders of the body of the bone. The body or shaft of the humerus is triangular to cylindrical in cut section and is compressed anteroposteriorly. It has 3 surfaces, namely: Its three borders are: The deltoid tuberosity is a roughened surface on the lateral surface of the shaft of the humerus and acts as the site of insertion of deltoideus muscle. The posterorsuperior part of

23506-451: The vertebrae at the front part were much taller but only slightly longer. The centra (vertebral bodies), the lower part of the vertebrae, were more elongated and roughly circular in cross section, while those of Giraffatitan were broader than tall. The foramina (small openings) on the sides of the centra, which allowed for the intrusion of air sacs, were larger than in Giraffatitan . The diapophyses (large projections extending sideways from

23667-426: The vertebral column of the trunk or torso is incompletely known, the back of Brachiosaurus most likely comprised twelve dorsal vertebrae; this can be inferred from the complete dorsal vertebral column preserved in an unnamed brachiosaurid specimen, BMNH R5937. Vertebrae of the front part of the dorsal column were slightly taller but much longer than those of the back part. This is in contrast to Giraffatitan , where

23828-477: The vertebral variation. Between 1991 and 2009, the name Giraffatitan was almost completely disregarded by other researchers. A detailed 2009 study by Taylor of all material, including the limb and girdle bones, found that there are significant divergences between B. altithorax and the Tendaguru material in all elements known from both species. Taylor found twenty-six distinct osteological (bone-based) characters,

23989-410: The very elongated neck ribs , which ran down the underside of the neck, overlapping several preceding vertebrae. These bony rods were attached to neck muscles at their ends, allowing these muscles to operate distal portions of the neck while themselves being located closer to the trunk, lightening the distal neck portions. Brachiosaurus and Giraffatitan probably had a small shoulder hump between

24150-428: Was warm-blooded . Among the most iconic and initially thought to be one of the largest dinosaurs , Brachiosaurus has appeared in popular culture , notably in the 1993 film Jurassic Park . The genus Brachiosaurus is based on a partial postcranial skeleton discovered in 1900 in the valley of the Colorado River near Fruita, Colorado . This specimen, which was later declared the holotype, comes from rocks of

24311-529: Was collected by the British Museum of Natural History 's Tendaguru expedition, including a nearly complete skeleton (BMNH R5937) collected by F.W.H. Migeod in 1930. This specimen is now believed to represent a new species , awaiting description. Janensch based his description of B. brancai on "Skelett S" (skeleton S) from Tendaguru, but later realized that it comprised two partial individuals: S   I and S   II. He at first did not designate them as

24472-453: Was derived from the Greek and had become a usual scientific designation for the chest of the body. The titles of Riggs's 1901 and 1903 articles emphasized that the specimen was the "largest-known dinosaur". Riggs followed his 1903 publication with a more detailed description in a monograph in 1904. Preparation of the holotype began in the fall of 1900 shortly after it was collected by Riggs for

24633-508: Was found in yellowish white sandstone, near a 1-meter-long (3 ft 3 + 1 ⁄ 2  in) cervical vertebra, which was destroyed during an attempt to collect it. The skull was cataloged as YPM 1986, and sent to Marsh at the Peabody Museum of Natural History , who incorporated it into his 1891 skeletal restoration of Brontosaurus (perhaps because Felch had identified it as belonging to that dinosaur). The Felch Quarry skull consists of

24794-406: Was later questioned by D'Emic and Carrano in 2019. They considered the referral of "Toni" to B. altithorax be based on mistaken interpretations of the species' unique features or of the specimen itself, and deemed it worthy of further study. Analyzing photos of the large foot, D'Emic and Carrano noted that the only feature that allowed referral to Brachiosauridae may have been influenced by damage to

24955-409: Was lost to erosion; its original length is estimated at 216 centimeters (85 in). This bone was more slender in Brachiosaurus than in most other sauropods, measuring only 28.5 centimeters ( 11 + 1 ⁄ 4  in) in width at its narrowest part. It was, however, more robust than that of Giraffatitan , being about ten percent broader at the upper and lower ends. At its upper end, it featured

25116-470: Was moved to the B   Concourse of United Airlines ' Terminal One in O'Hare International Airport to make room for the museum's newly acquired Tyrannosaurus skeleton, " Sue ". At the same time, the Field Museum mounted a second plastic cast of the skeleton (designed for outside use) which is on display outside the museum on the NW terrace. Another outdoor cast was sent to Disney's Animal Kingdom to serve as

25277-490: Was not as large as had been thought; the dimensions of the shoulder's coracoid bone indicate that the animal was smaller than Riggs's original specimen of Brachiosaurus . Several additional specimens were briefly described by Jensen in 1987. One of these finds, the humerus USNM 21903, was discovered in ca. 1943 by uranium prospectors Vivian and Daniel Jones in the Potter Creek Quarry in western Colorado, and donated to

25438-404: Was only after preparation of the fossil material in the laboratory that the bone was recognized as a humerus. The excavation attracted large numbers of visitors, delaying the work and forcing Menke to guard the site to prevent bones from being looted. On August 17, the last bone was jacketed in plaster. After a concluding ten-day prospecting trip, the expedition returned to Grand Junction and hired

25599-636: Was rejected by Daniel Chure in 2010, but from 2012 onward most studies recognized the name Giraffatitan . In 1947, at Atalaia in Portugal, brachiosaurid remains were found in layers dating from the Tithonian . Albert-Félix de Lapparent and Georges Zbyszewski named them as the species Brachiosaurus atalaiensis in 1957. Its referral to Brachiosaurus was doubted in the 2004 edition of The Dinosauria by Paul Upchurch, Barret, and Peter Dodson who listed it as an as yet unnamed brachiosaurid genus. Shortly before

25760-685: Was reported lost in 2013. It was not analyzed and provisionally considered to represent an indeterminate sauropod, until such time that it could be relocated in the collections of the Muséum national d'histoire naturelle . Only four out of the five sacral vertebrae are preserved. The total original length was in 1960 estimated at 1.3 meters (4 ft 3 in), compared to 0.91 meters (3 ft 0 in) with B. altithorax . This would make it larger than any other sauropod sacrum ever found, except those of Argentinosaurus and Apatosaurus . Most estimates of Brachiosaurus altithorax 's size are based on

25921-485: Was semicircular and taller than broad. Differences from Giraffatitan are related to its shape in side view, including the straighter suture with the scapula. Moreover, the articular surface that forms part of the shoulder joint was thicker and directed more sideward than in Giraffatitan and other sauropods, possibly indicating a more sprawled forelimb. The humerus, as preserved, measures 204 centimeters ( 80 + 1 ⁄ 2  in) in length, though part of its lower end

#10989