23-512: Dicraeosauridae is a family of diplodocoid sauropods who are the sister group to Diplodocidae . Dicraeosaurids are a part of the Flagellicaudata , along with Diplodocidae. Dicraeosauridae includes genera such as Amargasaurus , Suuwassea , Dicraeosaurus , and Brachytrachelopan . Specimens of this family have been found in North America, Asia, Africa, and South America. In 2023,
46-588: A basal dicraeosaurid, including Whitlock (2010) and Salgado et al. (2006). As sauropods, dicraeosaurids are obligate herbivores. Due to their relatively small necks and skull shape, it has been deduced that dicraeosaurids and diplodocids primarily browsed close to the ground or at mid height. Among the dicraeosaurids, only Dicraeosaurus has well-preserved dentition. This makes it difficult for paleontologists to make definitive statements about Dicraeosauridae feeding behavior compared to diplodocid feeding behavior. However, compared to its known relatives, Dicraeosaurus
69-769: A dicraeosaurid fossil was discovered in India for the first time. Their temporal range is from the Early or Middle Jurassic to the Early Cretaceous . Few dicraeosaurids survived into the Cretaceous, the youngest of which was Amargasaurus . The group was first described by German paleontologist Werner Janensch in 1914 with the discovery of Dicraeosaurus in Tanzania. Dicraeosauridae are distinct from other sauropods because of their relatively short neck size and small body size. The clade
92-620: A few bones available for study including an ulna, partial scapula, partial dorsal vertebrae, a distal radius, and some metacarpals. Dyslocosaurus polyonychius also has extremely limited fossil evidence that only includes appendicular elements, and the position of it in Tschopp's phylogeny is therefore considered "preliminary". Several studies, however, do not include even Suuwassea in Dicraeosauridae, such as Sereno et al. (2007); and JD Harris (2006). Other studies, however, recover Suuwassea as
115-554: A lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching a consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called
138-412: A low-level browser of vegetation no more than 3 metres (9.8 ft) off the ground. Dicraeosaurus also lacked the "whiplash" tail tip typical of diplodocoids. It was smaller than many other diplodocoids, at only 14–15 metres (46–49 ft) in length and 5–6 metric tons (5.5–6.6 short tons), though this still makes it among the larger known members of the family Dicraeosauridae. The genus is notable for
161-580: A new genus, Pilmatueia , was described. Dicraeosaurids are differentiated from their sister group, diplodocids, and from most sauropods by their relatively small body size and short necks. Dicraeosaurids are advanced sauropods within the monophyletic clade Neosauropoda , which is generally characterized by gigantism. The relatively small body size of dicraeosaurids make them an important outlier relative to other taxa in Neosauropoda. There have been several different proposed phylogenies of Dicraeosauridae and
184-468: Is monophyletic and well-supported phylogenetically with thirteen unambiguous synapomorphies uniting it. They diverged from Diplodocidae in the Mid-Jurassic, as evidenced by the diversity of dicraeosaurids in both South America and East Africa when Gondwana was still united by land. However, there is some disagreement among paleontologists on the phylogenetic placement of Suuwassea , the only genus of
207-465: Is a genus of diplodocoid sauropod dinosaur that lived in what is now Lindi Region , Tanzania during the late Jurassic period. The genus was named for the neural spines on the back of its neck. The first fossil was described by paleontologist Werner Janensch in 1914. Unlike most diplodocoids, Dicraeosaurus had a comparatively large head with a relatively short and wide neck. The neck contained 12 unusually short vertebrae , likely indicating
230-499: Is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to
253-480: Is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family
SECTION 10
#1732902522224276-423: Is unique in that it has an equal number of teeth in the upper and lower jaw, though teeth in the lower jaw are replaced more slowly. Dicraeosaurids are characterized by their relatively small body size, short necks, and long neural spines. They are 10–13 meters in body length. They share thirteen unambiguous synapomorphies including dorsal vertebrae without pleurocoels, the presence of a ventrally directed prong on
299-543: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Dicraeosaurus Dicraeosaurus (Gr. δικραιος , dikraios "bifurcated, double-headed" + Gr. σαυρος , sauros "lizard")
322-469: The Dicraeosauridae to be found in North America. It has been characterized as a basal dicraeosaurid by some and a member of the Diplodocidae by others. The placement of Suuwassea within Dicraeosauridae or Diplodocidae has substantial biogeographic implications for the evolution of Dicraeosauridae. Dicraeosaurids are a part of Diplodocoidea and are the sister group to Diploidocidae. In the past two decades,
345-588: The diplodocids in the middle Jurassic in North America and subsequently dispersed into Gondwana, with the most diversity in East Africa and South America. Amargasaurus was the latest surviving dicraeosaurid genus, living into the Early Cretaceous period. Recently from the Thar Desert , a dicraeosaurid fossil dating back to 167 million years ago was discovered in 2023. This present-day sweltering expanse of India
368-530: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
391-606: The intra-group cladistics are not resolved. Suuwassea is variably positioned as either a basal dicraeosaurid or a basal diplodocoid. The phylogeny published by Tschopp and colleagues in 2015 is as follows: Dyslocosaurus polyonychius Suuwassea emilieae Dystrophaeus viaemalae Brachytrachelopan mesai Amargasaurus cazaui Dicraeosaurus hansemanni Tschopp includes Dyslocosaurus and Dystrophaeus as dicraeosaurids, two genera traditionally not considered to be part of Dicraeosauridae. The specimens of Dystrophaeus viamelae are highly fragmentary, with only
414-423: The known diversity of the group has doubled. However, the classification of Suuwassea as a dicraeosaurid is not universally agreed upon. Some phylogenetic analyses have found Suuwassea to be a basal diplodocoid instead of a dicraeosaurid. One 2015 analysis has even found Dyslocosaurus as a member of Dicraeosauridae. A 2016 reappraisal of Amargatitanis has placed it into the Dicraeosauridae, as well. In 2018
437-575: The rather tall neural spines protruding from its vertebrae, which it is named for. They were not straight as in some members of the family, instead forming a rough "Y" shape. These spines likely provided muscle attachment points. Dicraeosaurus was a mid-sized herbivore for its ecosystem, found in the Tendaguru Formation of Tanzania , which dates to the Late Jurassic. The rocks also yield fossils of Giraffatitan and Kentrosaurus . As there
460-567: The seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted
483-538: The squamosal, and a subtriangular-shaped dentary symphysis. Early Dicraeosaurid specimens have been found in three continents - Africa, South America, and North America. The distribution of species is primarily Gondwonan, with the exception of the North American Suuwassea . The presence of Suuwassea in North America is unique among dicraeosaurids, therefore making the proper taxonomic classification of Suuwassea essential. The group likely first diverged from
SECTION 20
#1732902522224506-541: The use of this term solely within the book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
529-673: Was a lush green tropical coastline that bordered the Tethys Ocean , serving as a habitat for a diverse range of dinosaurs during the Mesozoic Era . This discovery marks the first of its kind to be unearthed in Asian continent and is also the oldest specimen ever recorded in the global fossil record. [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Family (biology) Family ( Latin : familia , pl. : familiae )
#223776