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78-482: Panderichthys is a genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian period, about 380 Mya . Panderichthys , which was recovered from Frasnian (early Late Devonian) deposits in Latvia , is represented by two species. P. stolbovi is known only from some snout fragments and an incomplete lower jaw. P. rhombolepis is known from several more complete specimens. Although it probably belongs to

156-557: A species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in the nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

234-613: A breath. The enlargement of the spiracular chamber itself as well as its opening to the outside suggests that Panderichthys was part of a transition to an increased capacity for air breathing that was completed in tetrapods. [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Genus The composition of a genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including

312-561: A fin, there are numerous lepidotrichia (long and thin fin rays). Panderichthys has many features that can be considered an intermediate form during the fish-tetrapod evolution and displays some features that are more derived than its phylogenetic position indicates, while others that are more basal. The body form of Panderichthys and Tiktaalik represents a major step in the transition from fish to tetrapods and they were even able to haul out on land. According to Shultze and Trueb, Panderichthys shares ten features with tetrapods: One of

390-494: A group of two meter long tetrapods lived in the fully marine intertidal or lagoonal areas on the south coast of Laurussia during the time elpistostegids were living. This implies that Panderichthys is not a transitional fossil and represents its own adaptive morphology. Therefore, Panderichthys can only be a "late-surviving relic", showing traits that evolved during the transition from fish-like creatures to tetrapods, but whose date does not reflect that transition. The tracks "force

468-413: A joint with the ulna bone. The corresponding bone in the lower leg is the tibia . The long narrow medullary cavity is enclosed in a strong wall of compact bone . It is thickest along the interosseous border and thinnest at the extremities, same over the cup-shaped articular surface (fovea) of the head. The trabeculae of the spongy tissue are somewhat arched at the upper end and pass upward from

546-412: A key intermediate within the fish-evolution sequence. From the outside, Panderichthys has a tetrapod-like head, but actually retains an intracranial joint that is a characteristic of fish. Panderichthys shares many features with the osteolepiform Eusthenopteron such as similar hyomandibular and basipterygoid processes. Even though its head is shaped similar to that of a tetrapod, tetrapod craniums lack

624-643: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

702-455: A lateral commissure, jugular groove, basicranial fenestra, arcual plate, and intracranial joint, all of which are present in Panderichthys . What this means is that there was no major change of the braincase construction since the first sarcopterygian, but instead there had been only changes in skull shape. This implies that the evolution of the braincase during the transition from fish-tetrapod

780-412: A lingual prearticular, three coronoids, and an adsymphsial plate dorsally. In addition, the teeth are of polyplocodont structure. As an intermediate in the fish-tetrapod evolution, Panderichthys had the capacity to breathe air. The trend from the early sarcopterygians to the first tetrapods was an increase in the size of the spiracular chamber and its opening to the outside. Compared to Eusthenopteron ,

858-621: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

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936-408: A long time, they have only recently been examined in full. The first time they were recognized as being phylogenetically closer to tetrapods than fish was by Shultze and Arsenault in 1985. Panderichthys is a 1.5–2 m (4 ft 11 in – 6 ft 7 in) long fish with a large tetrapod-like head that is flattened, narrow at the snout and wide in the back. The intracranial joint, which

1014-426: A low entepicondyle, and an intermediate entepicondylar canal. The humerus of Panderichthys is more derived than that of Tiktaalik because of the presence of a more preaxially oriented radial facet as well as a more slender shaft. One feature that is unique to Panderichthys is that the entepicondyle does not project as far as the epipodial facets and the humeral ridge does not go into the entepicondyle. The result of

1092-403: A more derived feature similar to tetrapods and unlike Tiktaalik : the ulna is significantly longer than the ulnare. The pelvic girdle (hip) and pelvic fins of Panderichthys represents an intermediate in the fish-tetrapod evolution. During the fish-tetrapod evolution the pelvic girdle became a weight bearing structure when the ilium, meso-ventral contact of the sides of the girdle, an ilium, and

1170-467: A radical reassessment of the timing, ecology and environmental setting of the fish–tetrapod transition, as well as the completeness of the body fossil record." Panderichthys was alive during the late Devonian ( Frasnian ) in Lode, Latvia. Lode is known to be a marginal marine environment and it has been hypothesized that Panderichthys was adapted for movement in shallow and debris filled waters. Panderichthys

1248-428: A reexamination of existing Panderichthys fossils using a CT scanner shows at least four very clearly differentiated distal radial bones at the end of the fin skeletal structure. This study, performed by Boisvert et al. in 2008, examined the pectoral fins of Panderichthys and found that the fins of Panderichthys are oriented anteroposteriorly, which is different from the limbs of tetrapods that project at an angle from

1326-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

1404-467: A sacral rib developed. The femur and humerus became longer and the radius/ulna and tibia/fibula became more equal in length. In general, the pelvic girdle in Panderichthys is more primitive than the pectoral girdle. This is due to the humerus of Panderichthys being a shape that is more of an intermediate, while the femur is more primitive because of the length ratio to the fibula and that it lacks an adductor blade and crest. This implies that Panderichthys

1482-487: A sister group of the earliest tetrapods , Panderichthys exhibits a range of features transitional between tristichopterid lobe-fin fishes (e.g., Eusthenopteron ) and early tetrapods. It is named after the German-Baltic paleontologist Christian Heinrich Pander . Possible tetrapod tracks dating back to before the appearance of Panderichthys in the fossil record were reported in 2010, which suggests that Panderichthys

1560-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1638-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

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1716-413: Is Latin for "ray". In the context of the radius bone, a ray can be thought of rotating around an axis line extending diagonally from center of capitulum to the center of distal ulna . While the ulna is the major contributor to the elbow joint, the radius primarily contributes to the wrist joint. The radius is named so because the radius (bone) acts like the radius (of a circle). It rotates around

1794-420: Is ossified from three centers: one for the body, and one for each extremity. That for the body makes its appearance near the center of the bone, during the eighth week of fetal life. Ossification commences in the lower end between 9 and 26 months of age. The ossification center for the upper end appears by the fifth year. The upper epiphysis fuses with the body at the age of seventeen or eighteen years,

1872-480: Is a triangular rough surface for the attachment of the volar radiocarpal ligament . At the junction of the upper and middle thirds of the volar surface is the nutrient foramen, which is directed obliquely upward. The dorsal surface ( facies dorsalis; posterior surface ) is convex, and smooth in the upper third of its extent, and covered by the Supinator . Its middle third is broad, slightly concave, and gives origin to

1950-519: Is actually a joint referred to as a syndesmosis joint. The volar surface ( facies volaris; anterior surface ) is concave in its upper three-fourths, and gives origin to the flexor pollicis longus muscle ; it is broad and flat in its lower fourth, and affords insertion to the Pronator quadratus . A prominent ridge limits the insertion of the Pronator quadratus below, and between this and the inferior border

2028-420: Is characteristic of most lobe-fin fishes, has been lost from the external elements of the skull, but is still present in the braincase. The patterns of external bones in the skull roof and cheeks are more similar to those of early tetrapods than those of other lobe-fins. The transitional qualities of Panderichthys are also evident in the rest of the body. It lacks the dorsal and anal fins ( fish fin ) and its tail

2106-596: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

2184-429: Is level to the shoulder joint, which causes the muscles to pull at a right angle to the body. This resulted in the ability of Panderichthys to prop up its large head most likely to breathe. Another key feature of Panderichthys is its intermediate form during the evolution of digits. In the past it was believed that digits and fingers had no analogous part in sarcopterygian fish and were evolutionary novelties. However,

2262-425: Is more like those of early tetrapods than the caudal fins of other lobe-fins. The shoulders exhibit several tetrapod-like features, while the humerus is longer than those found in other lobe-fins. The vertebral column is ossified throughout its length and the vertebrae are comparable to those of early tetrapods. On the other hand, the distal parts of the front fins are unlike those of tetrapods. As would be expected from

2340-681: Is not a direct ancestor of tetrapods, but nonetheless shows the traits that evolved during the fish-tetrapod evolution Panderichthys is represented by two different species: Panderichthys rhombolepis and Panderichthys stobolvi . P. rhombolepis was discovered by Gross in 1930 and P. stobolvi was discovered and figured by Emilia Vorobyeva in 1960. P. rhombolepis was discovered in Lode, Latvia within Frasnian deposits and according to P.E. Ahlberg can definitely be found in other Frasnian deposits in Latvia. Although fossils of Panderichthys have been known for

2418-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

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2496-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

2574-405: Is very similar. Both Panderichthys and Tiktaalik have humeri that are dorsoventrally flattened with a blade like entepicondyle curving ventrally, separated epipodial facets, a latissimus dorsi process and ectepicondule process that is parallel to the preaxial margin. The humeri of both species are considered transitional forms because they are almost L-shaped, have a low latissimus dorsi process,

2652-462: The Abductor pollicis longus above, and the extensor pollicis brevis muscle below. Its lower third is broad, convex, and covered by the tendons of the muscles which subsequently run in the grooves on the lower end of the bone. The lateral surface ( facies lateralis; external surface ) is convex throughout its entire extent and is known as the convexity of the radius , curving outwards to be convex at

2730-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

2808-799: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

2886-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

2964-407: The wrist and runs parallel to the ulna. The ulna is longer than the radius, but the radius is thicker. The radius is a long bone , prism -shaped and slightly curved longitudinally. The radius is part of two joints : the elbow and the wrist . At the elbow, it joins with the capitulum of the humerus , and in a separate region, with the ulna at the radial notch . At the wrist, the radius forms

3042-657: The Frasnian in which Panderichthys was extant, there was a drop in oxygen in the atmosphere as well as an increase in the abundance of plants. Due to the fact that oxygen is much less soluble in water than air, the decreased oxygen in the atmosphere would have caused the oxygen concentrations in any type of water to decrease substantially. This in turn would have caused any aquatic animal that could breathe air to have an advantage and be more likely to thrive. In addition to its ability to move in shallow water, Panderichthys could also breathe air. Its strong pectoral fins in theory could allow it to prop up its head in shallow water and take

3120-469: The French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or the scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of

3198-407: The analysis of the humerus of Panderichthys is that the transition of the humerus from the fish-like organisms to tetrapods occurred much slower than previously thought and Panderichthys now provides a base to determine many autapomorphies. Due to the orientation of the fin towards the posterior end, the attitude of the limb is more horizontal than vertical and the operational space in which it acts

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3276-403: The anterior and posterior margins of the ulnar notch . To the posterior of the two ridges the lower part of the interosseous membrane is attached, while the triangular surface between the ridges gives insertion to part of the pronator quadratus muscle . This crest separates the volar from the dorsal surface, and gives attachment to the interosseous membrane. The connection between the two bones

3354-532: The back of the neck, and ends below at the posterior part of the base of the styloid process ; it separates the posterior from the lateral surface. is indistinct above and below, but well-marked in the middle third of the bone. The interosseous border ( internal border; crista interossea; interosseous crest; ) begins above, at the back part of the tuberosity , and its upper part is rounded and indistinct; it becomes sharp and prominent as it descends, and at its lower part divides into two ridges which are continued to

3432-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

3510-401: The body attaches to the extensor ossis metacarpi pollicis , extensor primi internodii pollicis , and the pronator teres muscles. The lower quarter of the body attaches to the pronator quadratus muscle and the tendon of the supinator longus . Radial aplasia refers to the congenital absence or shortness of the radius. Specific fracture types of the radius include: The word radius

3588-449: The body. The humerus, radius , and ulna all are recognizable as analogous to the parts in tetrapods. CT scans allowed the authors to see below the scales and lepidotrichia (fin rays), uncovering the distal fin endoskeleton for the first time. The CT scan displayed an ulnare , a blocky carpal (wrist bone) that articulates with the ulna and two terminal radials. The wrist also included a more slender intermedium , articulating in line to

3666-409: The compact layer of the shaft to the fovea capituli (the humerus 's cup-shaped articulatory notch); they are crossed by others parallel to the surface of the fovea. The arrangement at the lower end is somewhat similar. It is missing in radial aplasia . The radius has a body and two extremities. The upper extremity of the radius consists of a somewhat cylindrical head articulating with the ulna and

3744-411: The evolution from fish to tetrapods. Sarcopterygians such as Panderichthys can be considered at least facultative air breathers and demonstrate an intermediate form as air breathing was becoming more abundant. In January 2010, Nature reported well-preserved and "securely dated" tetrapod tracks from Polish marine tidal flat sediments approximately 397 million years old. These fossil tracks suggest that

3822-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

3900-727: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

3978-445: The humerus and as a result early tetrapods have an L-shaped humerus. Due to a recent discovery of a humerus of Panderichthys that was not flattened, the specimen could be analyzed in much greater detail. The humerus of Panderichthys displays a variety of features including ones that are both primitive and derived. Despite being placed as basal to Tiktaalik , the humerus of Panderichthys has features that are more derived, but overall

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4056-488: The humerus, a neck, and a radial tuberosity . The body of the radius is self-explanatory, and the lower extremity of the radius is roughly quadrilateral in shape, with articular surfaces for the ulna , scaphoid and lunate bones . The distal end of the radius forms two palpable points, radially the styloid process and Lister's tubercle on the ulnar side. Along with the proximal and distal radioulnar articulations , an interosseous membrane originates medially along

4134-432: The idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of the same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but

4212-410: The key transitional features of Panderichthys is its humerus . During the transition from fish to tetrapods the limbs began to move and became located at a right angle to the body rather than being oriented toward the posterior end. As a result, the muscles became perpendicular to the body and caused the limbs to move in a more anteroposterior and dorsoventral pattern. This in turn affected the shape of

4290-628: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

4368-419: The lateral ridge of the ulna. The CT scan additionally uncovered radials that can be interpreted as digits, disputing the hypothesis that digits are entirely new structures in tetrapods. These finger-like bones show neither muscle development nor joints and they are extremely small, but nonetheless show an intermediate form between fully fish-like fins and tetrapods. Similar to the humerus, Panderichthys also has

4446-415: The length of the body of the radius to attach the radius to the ulna. The distal end of the radius is large and of quadrilateral form. It is provided with two articular surfaces – one below, for the carpus , and another at the medial side, for the ulna . These two articular surfaces are separated by a prominent ridge, to which the base of the triangular articular disk is attached; this disk separates

4524-406: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. Radius (bone) The radius or radial bone ( pl. : radii or radiuses ) is one of the two large bones of the forearm , the other being the ulna . It extends from the lateral side of the elbow to the thumb side of

4602-411: The lower about the age of twenty. An additional center sometimes found in the radial tuberosity , appears about the fourteenth or fifteenth year. The biceps muscle inserts on the radial tuberosity of the upper extremity of the bone. The upper third of the body of the bone attaches to the supinator , the flexor digitorum superficialis , and the flexor pollicis longus muscles. The middle third of

4680-410: The lower part of the tuberosity above to the anterior part of the base of the styloid process below, and separates the volar from the lateral surface. Its upper third is prominent, and from its oblique direction has received the name of the oblique line of the radius; it gives origin to the flexor digitorum superficialis muscle (also flexor digitorum sublimis ) and flexor pollicis longus muscle ;

4758-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

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4836-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

4914-526: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

4992-403: The side. Its upper third gives insertion to the supinator muscle . About its center is a rough ridge, for the insertion of the pronator teres muscle . Its lower part is narrow, and covered by the tendons of the abductor pollicis longus muscle and extensor pollicis brevis muscle . The upper extremity of the radius (or proximal extremity ) presents a head, neck, and tuberosity. The radius

5070-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

5148-472: The specimens are well preserved due to anaerobic substrate conditions as well as rapid burial in depressions on the submarine delta slopes. P. rhombolepis was discovered in the Gauja Regional formation within the lower Frasnian section. Taphocoenosis was characterized as in finely displaced clay and silty clay as well as low water activity. Within this environment it has been hypothesized that P. rhombolepis

5226-486: The spiracular chamber of Panderichthys is greatly expanded and the hyomandibula is shorter compared to those in fish. The opercular series was also shorter compared to other osteolepiforms. Panderichthys also has a single external nasal opening and a palatal choana. In contrast to earlier osteolepiforms, the palatal choana is elongated and the nariochoanal lamina is narrow. Along with the spiracular chamber, this feature in Panderichthys can be considered transitional during

5304-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

5382-447: The surface above the line gives insertion to part of the supinator muscle . The middle third of the volar border is indistinct and rounded. The lower fourth is prominent, and gives insertion to the pronator quadratus muscle , and attachment to the dorsal carpal ligament ; it ends in a small tubercle, into which the tendon of the brachioradialis muscle is inserted. The dorsal border ( margo dorsalis; posterior border ) begins above at

5460-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

5538-414: The ulna and the far end (where it joins to the bones of the hand), known as the styloid process of the radius, is the distance from the ulna (center of the circle) to the edge of the radius (the circle). The ulna acts as the center point to the circle because when the arm is rotated the ulna does not move. In four-legged animals, the radius is the main load-bearing bone of the lower forelimb. Its structure

5616-566: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

5694-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

5772-417: The wrist-joint from the distal radioulnar articulation. This end of the bone has three non-articular surfaces – volar, dorsal, and lateral. The body of the radius (or shaft of radius ) is prismoid in form, narrower above than below, and slightly curved, so as to be convex lateralward. It presents three borders and three surfaces. The volar border ( margo volaris; anterior border; palmar ;) extends from

5850-417: Was a large predator and fed upon dipterids, small and juvenile sarcopterygians, and Latvius . Associated vertebrates found in the same deposits include an armored jawless fish ( Psammolepis ), two placoderms ( Asterolepis and Plourdosteus ), an unidentified acanthodid acanthodian, a porolepiform lobe-fin ( Laccognathus ), a lungfish ( Dipterus ), and another elpistostegalian ( Livoniana ). During

5928-483: Was collected in deposits that were formerly believed to be from a calm freshwater basin, but have proven to be from shallow tidal flats or an estuary. The Lode Formation, where P. rhombolepis was found, occurs within a 200-meter thick layer composed of fine grained sandstone and clay along with finely dispersed clays. Nearly every major taxa of late Devonian vertebrates are represented within the Lode Formation. Most of

6006-416: Was not capable of tetrapod-like hindlimb propelled locomotion because of its small pelvic fins, non-weight bearing pelvic girdle, acetebelum oriented posteriorly, and limited knee and elbow flexion. Boisvert describes the locomotion of Panderichthys as possibly using one of its pectoral fins to anchor itself while side to side undulation propels the body forward. The braincase of Panderichthys demonstrates

6084-422: Was very rapid and seems to display the same timing as the evolution of the pelvic girdle. In general, Panderichthys demonstrates that the braincase structure evolved much more slowly than the external skull morphology that created the tetrapod-like appearance of the head. As for the lower jaw and dentition, the lower jaw is similar to Rhipidistians and is composed of a tooth-bearing dentary, four intradentaries,

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