Sauropod skulls are notoriously rare in the fossil record, because their heads were small and delicate compared to more robust skeletal features like vertebrae, femurs, or pelvic girdles.
|
|
The pectoral and pelvic girdles resemble those of the embolomere Proterogyrinus.
|
|
In Stethacanthus, the pelvic girdles consist of sheets of prismatic cartilage, each in the shape of a subtriangular, rounded plate. The anterior edge of each girdle is slightly concave while the posterior is convex. There appears to be no union of the two plates. There are two types of pelvic girdles found in stethacanthids: the primitive condition and the derived condition.
|
|
Tanystropheus longbardicus (Bassani) (Neue Egerbnisse). in Kuhn-Schnyder, E., Peyer, B. (eds) — Triasfauna der Tessiner Kalkalpen XXIII. Schweiz. Paleont. Abh. Vol. 95 Basel, Germany. The pectoral and pelvic girdles are notably distinct.
|
|
The axial skeleton, comprising the spine, chest and head, contains 80 bones. The appendicular skeleton, comprising the arms and legs, including the shoulder and pelvic girdles, contains 126 bones, bringing the total for the entire skeleton to 206 bones.
|
|
Geoemydidae are turtles of various sizes (from about in length) with often a high degree of sexual dimorphism. They usually have webbed toes, and their pelvic girdles articulate with their plastrons flexibly. Their necks are drawn back vertically. Their carapaces have 24 marginal scutes.
|
|
The limbs bore small conical studs. Pareiasaurs feature a short stout body, and a short tail. Scutosaurus has 19 presacral vertebrae. Pareiasaurs, as well as many other common herbivorous Permian tetrapods, had a large body, barrel- shaped ribcage, and engorged limbs and pectoral and pelvic girdles.
|
|
Tortoises are unique among vertebrates in that the pectoral and pelvic girdles are inside the ribcage rather than outside. Tortoises can vary in dimension from a few centimeters to two meters. They are usually diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals.
|
|
There are only two sacral vertebrae. The caudal vertebrae number at least seventeen, with very tall neural spines (taller than the centrum is) and low-attached caudal ribs. The holotype had all seventeen of the first caudal vertebrae articulated. Several pelvic girdles are known, with ventral acetabula and thickened peduncles.
|
|
Laramiensis Knight, American Jurassic Plesiosaurs. The Journal of Geology, 20, 4, 344-352. Muraenosaurus reedii was discovered in Wyoming and described by Maurice Mehl of the University of Chicago. The fossilized fragments found consisted of pieces of the pectoral and pelvic girdles, several vertebrae, ribs, and a relatively complete left pectoral paddle.
|
|
The shell is not an exoskeleton, but a modified ribcage and part of the vertebral column. Because of the shell, the pectoral and pelvic girdles are located within the ribcage. The limb bones are also modified to accommodate to the shell. The earliest known turtles are from fossils in the Upper Triassic.
|
|
The first few dorsals were short and almost all of the dorsals had bony prongs (transverse processes) sticking out of their sides. The tail is missing or incomplete in the described specimens. Specific details of the pectoral and pelvic girdles cannot be identified in the CT scans. The limbs are long and slender, with the hind limbs slightly longer than the front limbs.
|
|
The holotype fossil, SAM-PK-1070, is preserved in negative relief and has a partial skull, mandibles, axial skeleton, pectoral and pelvic girdles, osteoderms, and femur elements. The preserved femurs include a complete left and partial right. Partial skull elements present are the maxilla, quadrate, parabasisphenol, jugal, quadratojugal, mandible, and the palate. Little of the skull roof remains in this specimen.
|
|
Originally the pectoral and pelvic girdles, which do not contain any dermal elements, did not connect. In later forms, each pair of fins became ventrally connected in the middle when scapulocoracoid and puboischiadic bars evolved. In rays, the pectoral fins have connected to the head and are very flexible. One of the primary characteristics present in most sharks is the heterocercal tail, which aids in locomotion.
|
|
Fossils, 1 and 3 Erythrosuchus is known from many specimens, most of which are fragmentary. The holotype, described by Robert Broom in 1905 and known as SAM 905, is poorly preserved. Only small pieces of the limbs, pectoral and pelvic girdles, skull, and a few vertebrae present in this specimen. A thorough description of the genus was given by German paleontologist Friedrich von Huene in 1911.
|
|
Two of the juvenile individuals of the aggregate have radii with a slightly bowed shape. The metacarpals and phalanges of H. scholtzi have a long and slender shape to them. Pelvic girdles are preserved in both fossils and shows the anteroposteriorly elongated ischium typical of synapsids as well as a blade like distal shape and a well-developed pubic foramen. The ilium is also elongated and rises anteriorly above the acetabulum.
|
|
The sauropod Huabeisaurus was excavated from Upper Cretaceous sediments of the province of Shanxi, in northeast China. The skeleton was recovered in the 1990s. The holotype of Huabeisaurus is a partially articulated individual composed of teeth, cervical, dorsal, sacral, and caudal vertebrae, ribs, complete pectoral and pelvic girdles, and nearly complete limbs. Due to its relative completeness, Huabeisaurus represents a significant taxon for understanding sauropod evolution in Asia.
|
|
Plesiosaurs as the food of mosasaurs; new data on the stomach contents of a Tylosaurus proriger (Squamata; Mosasauridae) from the Niobrara Formation of western Kansas. The Mosasaur 7:41-46.). Lingham-Soliar suggested that tylosaurines were not among the fastest swimming nor the strongest mosasaurids. However, they are lightly built, having greatly reduced the weight of their bodies and possessing relatively small pectoral and pelvic girdles, fore- and hindlimbs.
|
|
Life restoration Albertonectes is known solely from the holotype TMP 2007.011.0001, a complete well preserved postcranial skeleton housed at the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta. Elements include all 132 vertebrae from the atlas-axis complex to fused tip of the tail vertebrae, complete pectoral and incomplete pelvic girdles, almost complete forelimbs and hindlimbs, disarticulated ribs, a gastralium, and at least 97 associated gastroliths. TMP 2007.011.
|
|
While the shoulder and pelvic girdles are missing with the exception of one ilium, the limbs are better known, including the humerus, ulna, radius, thigh bone, tibia, fibula, astragalus, and a claw from the hind foot. The forelimbs were proportionally longer than in the shortnecked Shunosaurus, but shorter than in Omeisaurus: the length ratio between humerus and thigh bone was 0.72 in Yuanmousaurus, while it was 0.56 in Shunosaurus and 0.80 in Omeisaurus.
|
|
The ribs form antero-ventral and postero-dorsal flanges, which are for the muscle attachments. Orthosuchus has similar pectoral girdles and pelvic girdles compare to living crocodiles, with a long scapula and a shorter coracoid. The interclavicle is hypothesized to be cartilaginous. As for the forelimb, the fossil records showed that Orthosuchus has similar humerus, but the distal and proximal expansions does not lay on the same plane as the modern crocodiles.
|
|
Among the elopomorphs, eels have elongated bodies with lost pelvic girdles and ribs and fused elements in the upper jaw. The 200 species of osteoglossomorphs are defined by a bony element in the tongue. This element has a basibranchial behind it, and both structures have large teeth which are paired with the teeth on the parasphenoid in the roof of the mouth. The clade Otocephala includes the Clupeiformes (herrings) and Ostariophysi (carps, catfishes and allies).
|
|
Pelophylax esculentus showing bones of the head, vertebral column, ribs, pectoral and pelvic girdles, and limbs. Frogs have no tail, except as larvae, and most have long hind legs, elongated ankle bones, webbed toes, no claws, large eyes, and a smooth or warty skin. They have short vertebral columns, with no more than 10 free vertebrae and fused tailbones (urostyle or coccyx). Like other amphibians, oxygen can pass through their highly permeable skins.
|
|
It also possesses a great number of additional autapomorphies, including a reduced and presumably nonfunctional third finger, consisting of only one rudimentary phalanx. The partial skeleton was collected from the red floodplain mudstone of the Sebeș Formation of Romania. It consists of a variety of vertebrae, as well as much of pectoral and pelvic girdles, and a large part of the limbs. It is the first reasonably complete and well- preserved theropod from the Late Cretaceous of Europe.
|
|
Pachyophis is an extinct genus of Simoliophiidae snakes that were extant during the Late Cretaceous period. More specifically, it was found to be from the Cenomanian Age about 93.9-100.5 million years ago in the suburb area of Bileca, Herzegovina. Pachyophis belongs to the family Simoliophiidae (hind- limbed snakes) in the clade Ophidia. The family is characterized by the presence of hindlimbs and pelvic girdles, as seen in Pachyrhachis (one of the first discovered hind-limbed snakes).
|
|
Compared with most sauropods, a relatively large amount of juvenile material is known from Apatosaurus. Multiple specimens in the OMNH are from juveniles of an undetermined species of Apatosaurus; this material includes partial shoulder and pelvic girdles, some vertebrae, and limb bones. OMNH juvenile material is from at least two different age groups and based on overlapping bones likely comes from more than three individuals. The specimens exhibit features that distinguish Apatosaurus from its relatives, and thus likely belong to the genus.
|
|
The holotype, PIN 3386/8, is a skull, which is well preserved on the left side, as well as some postcranial material consisting of pieces of the hands, feet, shoulder and pelvic girdles. A more fragmentary skull was also recovered, associated with some ribs, fragmentary vertebrae, and a complete forelimb. A third specimen preserves many limb bones and a series of 34 tail vertebrae from a smaller individual. Two even smaller fragmentary skeletons, presumably of young individuals, were uncovered nearby.
|
|
In 1986 a three-dimensional reconstruction of the holotype skeleton was completed and is now displayed at the ANSP. This cast was later copied by the company Triebold Paleontology Incorporated, and replicas were provided to other museums. One of these measures about in length. generic name refers to these "plate" bones Though Cope described and figured the pectoral and pelvic girdles of Elasmosaurus in 1869 and 1875, these elements were noted as missing from the collection by the American paleontologist Samuel Wendell Williston in 1906.
|
|
The mandibular symphysis (where the two halves of the lower jaw connected) was well ossified, with no visible suture. The pectoral and pelvic girdles of the holotype specimen were noted as missing by 1906, but observations about these elements were since made based on the original descriptions and figures from the late 19thcentury. The shoulder blades (scapulae) were fused and met at the midline, bearing no trace of a median bar. The upper processes of the shoulder blades were very broad, and the "necks" of the shoulder blades were long.
|
|
Other elements of the fossil included the anterior cervical vertebrae, partial dorsal and caudal vertebrae, incomplete fore and hind limbs, gastralia, partial pectoral and pelvic girdles, and ribs. The fossil was found in the Bearpaw Formation, a late Campanian/early Maastrichtian rock, making it one of the last known elasmosaurids to have lived in the Western Interior Seaway. N. bradti was only in length, making it one of the smallest elasmosaurids known. It also had a much shorter neck that most eleasmosaurids, with only 39 to 42 cervical vertebrae.
|
|
A juvenile specimen of A. wushaensis was described in 2007, making Anshunsaurus the only thalattosaur with a known growth series other than Xinpusaurus. The pectoral and pelvic girdles are asymmetrical in this specimen, suggesting that the bones on the left and right sides of the animal did not ossify at the same rate while it was growing. In 2007 a third species of Anshunsaurus, A. huangnihensis, was described from Xingyi. It is distinguished from the other two species on the basis of the shape of its coracoid, a bone of the pectoral girdle.
|
|
Dongbeititan is a genus of sauropod dinosaur from the Early Cretaceous-age Yixian Formation of Beipiao, Liaoning, China. It is based on holotype DNHM D2867, a partial postcranial skeleton including bones from the limbs, shoulder and pelvic girdles, and vertebrae. which was described in 2007 Its describers suggested it was as a basal titanosauriform, not as derived as Gobititan or Jiutaisaurus, but more derived than Euhelopus, Fusuisaurus, and Huanghetitan. The type species is D. dongi, and it is the first named sauropod from the Yixian Formation, which is part of the well-known Jehol Group.
|
|
Parayunnanolepis xitunensis is an extinct, primitive antiarch placoderm. The fossil specimens, including a marvelously preserved, intact specimen, are known from the Lochkovian Epoch-aged Xitun formation of Early Devonian Yunnan. The armor is very similar to that of Yunnanolepis, but is distinguished by being comparatively more flattened. An intact and exquisitely preserved specimen demonstrates that the living animal had pelvic fins and a pelvic girdle, thus proving that antiarchs had, primitively at least, pelvic girdles, and or inherited them from a common ancestor of both placoderms and other gnathostomes.
|
|
The specimen preserved almost 70% of the skeleton, and included most of the vertebral column, the pectoral and pelvic girdles, the femora, and the left tibia and fibula. In 1995, this specimen (MUCPv-Ch1) was preliminarily described by Coria and Salgado, who made it the holotype of the new genus and species Giganotosaurus carolinii (parts of the skeleton were still encased in plaster at this time). The generic name is derived from the Ancient Greek words gigas/γίγας (meaning "giant"), notos/νότος (meaning "austral/southern", in reference to its provenance) and -sauros/-σαύρος (meaning "lizard"). The specific name honors Carolini, the discoverer.
|
|
In the primitive condition, the pelvic girdles have a metapterygial element supporting only one or two radials and most of the fin radials are attached directly to the pelvic plate. The derived condition differs in that there is a much higher number of radials supported by the pelvic plate. This feature, accompanied with a broadening of the pelvic girdle in order to accommodate the increased number of radials is a characteristic of Stethacanthus and other symmorriids. The males had claspers that were club-shaped at the distal ends and composed of non-prismatic globular calcified cartilage.
|
|
Only one incomplete Elasmosaurus skeleton is definitely known, consisting of a fragmentary skull, the spine, and the pectoral and pelvic girdles, and a single species is recognized today; other species are now considered invalid or have been moved to other genera. Measuring long, Elasmosaurus would have had a streamlined body with paddle-like limbs, a short tail, a small head, and an extremely long neck. The neck alone was around long. Along with its relative Albertonectes, it was one of the longest-necked animals to have lived, with the largest number of neck vertebrae known, 72.
|
|
Aardonyx compared to a human in size The genus is known from disarticulated bones belonging to two immature individuals. The material consists of cranial elements, vertebrae, dorsal and cervical ribs, gastralia, chevrons, elements of the pectoral and pelvic girdles, and bones of the fore and hind limbs, manus, and pes. The presence of these bones in a single dense accumulation in a localized channel fill suggests that they came from relatively complete carcasses. Both individuals are thought to have been less than 10 years old at the time of their death because of the lack of peripheral rest lines in the cortices of sampled bones.
|
|
Majiashanosaurus is known solely from the holotype AGM-AGB5954, a nearly complete and articulated postcranial skeleton missing, apart from the skull, some neck vertebrae and a small portion of the tail. This skeleton is exposed in ventral view, i.e. from below, and preserves the last three neck vertebrae together with 19 back, three sacral, and more than 18 tail vertebrae, as well as pectoral and pelvic girdles, most of the forelimbs and hindlimbs, and ribs. AGM-AGB5954 was collected at Majiashan, Chaohu of Anhui Province, from the Upper Member of the Nanlinghu Formation, dating to the late Olenekian stage (Spathian) of the late Early Triassic, about 248 million years ago.
|
|
Chaoyangopterus is based on holotype IVPP V13397, which includes the front of the skull, the lower jaws, the neck vertebrae, the shoulder and pelvic girdles, and the limbs. The skull is about 270 millimeters long (10.6 inches) and toothless, and its wingspan is estimated to have been around 1.85 meters (6.07 feet). Wang and Zhou concluded that it compared most closely to Nyctosaurus and classified it as a nyctosaurid, although they found that its shin was proportionally longer compared to the femur and humerus in Chaoyangopterus, that their animal had relatively shorter wings and longer legs than Nyctosaurus, and that it still had four fingers.
|
|
Burnetiamorphs, which made up the majority of biarmosuchian diversity, were characterized by elaborate cranial ornamentation consisting of bumps and bosses. Some burnetiids have a thick domed skull reminiscent of dinocephalians and pachycephalosaur dinosaurs. The vertebrae are also sphenacodontid-like (but lack the long neural spines that distinguish Dimetrodon and its kin), but the shoulder and pelvic girdles and the limbs indicate a much more advanced posture. The feet are more symmetrical, indicating that they faced forward throughout the stride, and the phalanges (fingers/toes) are reduced in length so that they are more like that of later synapsids (therapsids and mammals) (Carroll 1988 pp. 370–1).
|
|
The skeleton is fairly complete, consisting of various parts of the skull, most of the vertebrae, several isolated ribs and gastralia, parts of the pectoral and pelvic girdles, both humeri, one femur, and various foot bones from the flippers. Over time, a number of parts have been lost, including several pieces of the skull, teeth, gastralia and caudal vertebrae, a second femur, and a radius, tibia, and fibula. A wax endocast of the brain of the type specimen is stored as SMF R4076 in the Naturmuseum Senckenberg. The clay pit from which the type specimen originates is part of the Isterberg Formation in the Bückeberg Group, also known in the past as the "German Wealden facies".
|
|
Another is an adaptive immune system that uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene. It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins.New study showing pelvic girdles arose before the origin of movable jaws Until recently these ancestors, known as antiarchs, were thought to have lacked pectoral or pelvic fins. In addition to this, some placoderms were shown to have a third pair of paired appendages, that had been modified to claspers in males and basal plates in females—a pattern not seen in any other vertebrate group.
|
|
The landscape of the Indian state of Gujarat, in which the remains of Rahiolisaurus were found During two expeditions, one in 1995 and the other in 1997, numerous remains of abelisaurids were recovered from a single quarry 50 square metres in area. The collected remains included cervical, dorsal, sacral, and caudal vertebrae, portions of pectoral and pelvic girdles, and several hind limb bones. Because of the unearthing of seven differently sized right tibiae, it was suggested that the assemblage was formed by at least seven individuals of different ontogenetic stages. Within the collection were several duplicate bones, such as the ilia, pubes, femora and tibiae, that exhibited similar morphological features of typical abelisauroid traits.
|
|
Silhouette reconstruction of the skeleton of L. marayensis Skull of L. marayensis in dorsal view Leyesaurus is known from the holotype PVSJ 706, a nearly complete skull with articulated mandible and some postcranial remains (vertebral column, scapular and pelvic girdles and hindlimb). The skull has a length of 18 centimeters, and Leyesaurus has been estimated to have been about in length. It was collected from the uppermost part of the Quebrada del Barro Formation of the Marayes-El Carrizal Basin, dating to the Lower Jurassic (based on the presence of a massospondylid like Leyesaurus within the formation). Leyesaurus was found near the locality Balde de Leyes, in the Caucete Department of San Juan Province.
|
|
Newer research suggests that a branch of Placoderms was most likely the ancestor of present- day gnathostomes. A 419-million-year-old fossil of a placoderm named Entelognathus had a bony skeleton and anatomical details associated with cartilaginous and bony fish, demonstrating that the absence of a bony skeleton in Chondrichthyes is a derived trait.Scientists make jaw dropping discovery The fossil findings of primitive bony fishes such as Guiyu oneiros and Psarolepis, which lived contemporaneously with Entelognathus and had pelvic girdles more in common with placoderms than with other bony fish, show that it was a relative rather than a direct ancestor of the extant gnathostomes. It also indicates that spiny sharks and Chondrichthyes represent a single sister group to the bony fishes.
|
|
Apart from electric rays, which have a thick and flabby body, with soft, loose skin, chondrichthyans have tough skin covered with dermal teeth (again, Holocephali is an exception, as the teeth are lost in adults, only kept on the clasping organ seen on the caudal ventral surface of the male), also called placoid scales (or dermal denticles), making it feel like sandpaper. In most species, all dermal denticles are oriented in one direction, making the skin feel very smooth if rubbed in one direction and very rough if rubbed in the other. Originally, the pectoral and pelvic girdles, which do not contain any dermal elements, did not connect. In later forms, each pair of fins became ventrally connected in the middle when scapulocoracoid and puboischiadic bars evolved.
|
|
Size of S. productus Stethacanthus was about long, and in many respects, had a shark-like appearance. However, it is best known for its unusually shaped dorsal fin, which resembled an anvil or ironing board. Small spikes (enlarged versions of the dermal denticles commonly covering shark skin) covered this crest, and the ratfish's head as well. The crest may have played a role in mating rituals, aided in clamping to the belly of larger marine animals, or been used to frighten potential predators.Elasmo-research Like other members of Stethacanthidae, Stethacanthus had unique pelvic girdles, single-crowned and non-growing scales, a pectoral fin composed of metapterygium with an accompanying ‘whip’ attached and a distinctive first dorsal fin and spine, termed the spine-brush complex.
|
|
Pliosaur/plesiosaur swim cycle animation, based on Hawthorne-McMenamin (revised version published May, 2017) In 2019, an innovative interpretation of plesiosaur locomotion surfaced when paleo-novelist Max Hawthorne, Mark McMenamin, and Paul de la Salle published an updated version of their 2017 study. Hawthorne and co-authors concluded that all four flippers were used simultaneously for locomotion, per Robinson's model and Sanders & Carpenter's study. However, inversed angling of the pectoral and pelvic girdles, as well as adaptive rib shortening that was characteristically more pronounced over the rear paddles, suggested that the front and rear flippers traveled through differing planes of motions, particularly during the positive stroke. This allowed the animal to maximize the benefits of two sets of paddles by pushing water through separate planes of motion.
|
|
In addition to these early trackways providing additional evidence of tetrapod activity on land as early as the Devonian, recent work has also been aimed at gleaning biomechanical interpretations from these occurrences. Typically, it is assumed that the earliest tetrapods had a movement pattern very similar to modern amphibians where the entirety of the pectoral and pelvic girdles would swing as the animal moved forward causing the angular pattern seen in these trackways. Although this movement is quite common in animals such as salamanders, recent work has also been done showing similar patterns created by terrestrially locomoting actinopterygian and sarcopterygian fish. In animals such as the actinopterygian cavefish, the alternating footfalls and general layout of the ancient trackways was readily reproduced.
|
|
Lehman for describing for the first time vertebrate material from the Triassic of Algeria. The holotype of Jesairosaurus lehmani is ZAR 06, a partial skeleton including an articulated and three-dimensionally preserved skull, pectoral girdle, cervical (neck) vertebrae, and a partial left humerus (forearm bone). It is also known from nine paratypes including ZAR 07 (a partial skull), ZAR 08 (a partial skull and postcranial skeletons), ZAR 09 (two partial postcranial skeletons), and ZAR 10-15, various postcranial material including vertebrae, pectoral and pelvic girdles, and even a partial hindlimb in ZAR 15. These specimens were collected in the Gour Laoud, locality 5n003 from the base of lower sandstones of the Lower Zarzaïtine Formation of Zarzaïtine Series, dating to the Anisian-Olenekian stages of the Early to the Middle Triassic.
|
|
Vegasaurus is known solely from the holotype MLP 93-I-5-1, a nearly complete well preserved postcranial skeleton (lacking the tip of the tail) housed at the La Plata Museum in La Plata, Argentina. Elements include the whole neck with 54 complete cervical vertebrae, three pectoral vertebrae, 17 back vertebrae, three sacral vertebrae, the front and middle tail vertebrae, pectoral and pelvic girdles, forelimbs and hindlimbs, ribs, and 45 gastroliths associated with the dorsal region. MLP 93-I-5-1 was discovered in 1989, by Eduardo Olivero, Daniel Martinioni, Francisco Mussel and Jorge Lusky, at Cape Lamb of Vega Island at the edge of the Antarctic Peninsula of James Ross Archipelago (northernmost part of Antarctica). Excavations took places during three Antarctic summer expeditions in 1993, 1999 and 2005.
|
|
SAM 5882, the holotype for Mesosuchus, consists of a partial rostrum, palate, braincase, lower jaws, sections of articulated presacral vertebral column, nine articulated caudal vertebrae, portions of scapula and pelvic girdle, and partial forelimb and hindlimbs. SAM 6046, one of the paratypes of Mesosuchus, consists of an incomplete right maxilla, an articulated series of the last ten presacrals, both sacrals, and first six caudals, partial forelimbs, left and right pelvic girdles, right hind limb, as well as element of left tarsus. SAM 6536, another paratype, consists of a virtually complete skull with lower jaws, articulated cervical vertebrae and ribs, dorsal vertebrae and ribs, complete left scapulocoracoid and partial right scapula, interclavicle, clavicles, distal end of left humerus, and gastralia. 50px This article contains quotations from this source, which is available under the Creative Commons Attribution 4.0 International (CC BY 4.0) license.
|
|
Restoration of L. paludis These early descriptions framed Limnoscelis as a member of the paraphyletic clade Captorhinomorpha within the Cotylosauria, alongside the clades Diadectomorpha and Seymouriamorpha. However, these early authors also noted many similarities between Limnoscelis and the diadectid Diadectes, including the bones forming the orbital border, the presence of a glenoid foramen on the scapula, and having similar pectoral and pelvic girdles. Differences were noted as well, including having a single continuous rib articulation rather than double-headed ribs, its conical teeth and carnivorous diet, the lack of a fused astragalus, and the presence of two fused coracoid elements rather than a single element in the coracoid plate. Despite these differences, the similarities with Diadectes would eventually be used to place Limnoscelis at its current taxonomic position as a diadectomorph, with Limnoscelidae erected as a family within the order Diadectomorpha alongside the family Diadectidae and the genus Tseajaia from the monogeneric family Tseajaiidae.
|
|