Fodonyx Temporal range: Middle Triassic, | |
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Restoration of F. spenceri compared to a human | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Order: | † Rhynchosauria |
Family: | † Hyperodapedontidae |
Genus: | † Fodonyx Hone & Benton, 2008 |
Species | |
Fodonyx (meaning "digging claw") is an extinct genus of rhynchosaur from the middle Triassic epoch of Devon in England. [1] Its fossils (25 specimens) were discovered in Otter Sandstone Formation (late Anisian age) and were first assigned to Rhynchosaurus spenceri . This species was reassigned to its own genus, Fodonyx (the type and only species is Fodonyx spenceri) the holotype of which is EXEMS 60/1985/292, that described by David W. E. Hone and Michael J. Benton in 2008. [1] In 2010, one skull was reassigned to the new genus Bentonyx . [2] It is distinguished from other rhynchosaurs by a single autapomorphy, the ventral angling of the paraoccipital processes. In all other rhynchosaurs these processes angle dorsally or are horizontal. It is not known if this conferred any advantage to Fodonyx. Fodonyx was between 40 and 50 cm long. [1]
The two premaxillae are very long and run up over the snout to meet the prefrontals at the orbit. At the anterior tip they are narrow and triangular in cross-section. They form the classic rhynchosaurian beak, and there is evidence on the fossil showing that it was probably covered by a keratinous sheath. The maxilla carries a massive tooth plate and has numerous foramina for nerves and blood vessels to reach the gums through. Many of the posterior and lateral teeth are unworn from use, unlike the more anterior teeth which have been worn smooth. The nasal bones are large, but no wider than the frontals. They form a pointed posterior tip with a strong zigzag suture. The lacrimal ducts are clearly visible next to the orbit, while the lacrimal bones form much of the interior surface of the orbit. The prefrontal forms a thick eyebrow ridge, possibly as protection from predators. The jugal is complex, with four branches, and forms the anterior and ventral margins of the lower temporal fenestra. The dorsal branch forms a strong pillar behind the orbit, which has a more pronounced crest than other rhynchosaurs. The frontals are very long, and form a dish shape posteriorly. The postfrontal is triangular and forms part of the back of the orbit. The parietals are fused and have a high narrow ridge dorsally, with lateral wings extending across the upper temporal fenestrae. The postorbitals are roughly T-shaped, with three branches. Unlike Late Triassic forms, Fodonyx has a supratemporal bone. The quadratojugal and quadrate are mainly missing. One squamosal is preserved, forming much of the posterior margin of the skull. Much of the palate is intact, although the vomeronasals are quite degraded due to their length and thinness. The palatines form most of the borders of the choana. The pterygoids are very large and have three main processes, all broad and flat. The ectopterygoids are very small and hidden in palatal view. Small fragments of the hyoids are preserved, with a circular cross section and lateral striations. The basioccipital is short and attached to the narrow basisphenoid. The occipital condyle is hemispherical. Much of the detail on the paraoccipital is hard to make out due to difficulties of preparation. Only the anterior portions of the lower jaw are well preserved, but it has the typical rhynchosaur shape, curving up to the anterior tip. Teeth are mainly obscured as the jaws are tightly shut. The splenial is narrow except at the tip where it supports the symphyseal plate. [1]
Cervical and sacral vertebrae are not known, only dorsal and caudal. The dorsal vertebrae have round centra which narrow noticeably towards the centre of the bone, and are deeply amphicoelous. They lack a keel, but have a deep excavation in the floor of the neural canal. Neural arches are around 15 mm tall, with narrow pillars supporting the zygapophyses, and are attached by broad flat facets. The zygapophyses are almost circular and very flat, which would allow side-to-side movement but little up-and-down movement. Three chevrons are preserved. The dorsal elements have fused to create a triangular opening. [1]
Many ribs are present, although partially fragmented, and show that the ribs were robust and the rib cage deep. They were also remarkably straight, at least at the anterior. There are also many gastralia, although these are quite jumbled together, and appear to be made of three segments. The gastral basket is almost entirely disarticulated. [1]
The scapulae have broad blades, and prominent bosses where the clavicles may have attached. Much of the front limbs are missing, but the humeri were broad and not very long, with an oval cross-section. [1]
The pelvis is incomplete, with the ilium clearly showing growth lines. The ischium has a thick round dorsal margin and a curved blade. The femur is missing, but the remainder of the hindlimb is present. The tibia is fairly long but quite thin, with a compressed oval cross-section. It shows heavy wear, and has a distinct twist where it probably attached to the fibula. This is more slender than the tibia, but still relatively robust. All the proximal tarsals and three of the distal tarsals are present, but are worn and broken. In general, they are quite rounded. The first metatarsal is short and broad but the other four are long and flat, although they are broken so it is hard to say exactly how long. The toes have, respectively, 2,3,4,5 and 4 phalanges. These all narrow as they head towards the claws. The unguals are all very large and broad, and have rounded ends without a recurve. Each ungual bears a shallow groove along the sides, probably for locking the keratin sheath. [1]
Lesothosaurus is a monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from Lesotho". The genus has only one valid species, Lesothosaurus diagnosticus. Lesothosaurus is one of the most completely-known early ornithischians, based on numerous skull and postcranial fossils from the Upper Elliot Formation. It had a simpler tooth and jaw anatomy than later ornithischians, and may have been omnivorous in some parts of the year.
Rhynchosaurs are a group of extinct herbivorous Triassic archosauromorph reptiles, belonging to the order Rhynchosauria. Members of the group are distinguished by their triangular skulls and elongated, beak like premaxillary bones. Rhynchosaurs first appeared in the Early Triassic, reaching their broadest abundance and a global distribution during the Carnian stage of the Late Triassic.
Hyperodapedon is an extinct genus of rhynchosaur reptiles which lived during Late Triassic period. Like other rhynchosaurs, it was an heavily built archosauromorph, distantly related to archosaurs such as crocodilians and dinosaurs. Hyperodapedon in particular was part of the subfamily Hyperodapedontinae, a specialized rhynchosaurian subgroup with broad skulls, beaked snouts, and crushing tooth plates on the roof of the mouth.
Calyptosuchus is an extinct genus of aetosaur from the Late Triassic of North America. Like other aetosaurs, it was heavily armored and had a pig-like snout used to uproot plants.
Chimaerasuchus is an extinct genus of Chinese crocodyliform from the Early Cretaceous Wulong Formation. The four teeth in the very tip of its short snout gave it a "bucktoothed" appearance. Due its multicusped teeth and marked heterodonty, it is believed to have been an herbivore. Chimaerasuchus was originally discovered in the 1960s but not identified as a crocodyliform until 1995, instead thought to possibly be a multituberculate mammal. It is highly unusual, as only two other crocodyliforms have displayed any characteristics resembling its adaptations to herbivory.
Acaenasuchus is an extinct genus of pseudosuchian, endemic to what would be presently be known as Arizona during the Late Triassic, specifically during the Carnian and Norian stages of the Triassic. Acaenasuchus had a stratigraphic range of approximately 11.5 million years. Acaenasuchus is further categorized as one of the type fauna that belong to the Adamanian LVF, based on the fauna of the Blue Mesa Member of the Chinle Petrified Forest Formation of Arizona, where Acaenasuchus was initially discovered.
Anatosuchus is an extinct genus of notosuchian crocodyliforms discovered in Gadoufaoua, Niger, and described by a team of palaeontologists led by the American Paul Sereno in 2003, in the Journal of Vertebrate Paleontology. Its duck-like snout coincidentally makes it resemble a crocoduck, an imagined hybrid animal with the head of a crocodile and the body of a duck.
Mesosuchus is an extinct genus of basal rhynchosaur from early Middle Triassic deposits of Eastern Cape, South Africa. It is known from the holotype SAM 5882, a partial skeleton, and from the paratypes SAM 6046, SAM 6536, SAM 7416 and SAM 7701 from the Aliwal North Euparkeria site. Mesosuchus is quite small, spanning around 30 cm in length. Mesosuchus was discovered and named by D. M. S. Watson in 1912.
Wadiasaurus is an extinct genus of dicynodont from the family Kannemeyeria, that lived in herds from the early to Middle Triassic. Substantial fossorial evidence of W. indicus was recovered from Yerrapalli Formation of the Pranhita-Godavari valley, India, and it is so far the only Kannemeyeriid known for certain from India. The Kannemeyeriiformes underwent a significant diversification during the middle Triassic, with roughly 40 known species distributed worldwide. All Kannemeyeriiformes were medium to large bodied, graviportal herbivores with relatively erect posture and gait. Wadiasaurus indicus is currently the only known species of Wadiasaurus.
Rhynchosaurus is a genus of rhynchosaur that lived during the Middle Triassic period. It lived in Europe. It was related to the archosaurs, but not within that group. The type species of Rhynchosaurus is R. articeps. Michael Benton named two additional species, R. spenceri and R. brodiei, but they were subsequently renamed Fodonyx and Langeronyx respectively. Fossils of Rhynchosaurus have been found in the Tarporley Siltstone Formation and possibly the Sherwood Sandstone Group of the United Kingdom.
Phantomosaurus is an extinct genus of ichthyosaur that lived during the late Anisian stage of the Middle Triassic. Fossils have been found in southern Germany. It was discovered in 1965 and named in 1997 as a species of Shastasaurus by Sander in the rocks of the Upper Muschelkalk.
Polonosuchus is a genus of rauisuchid known from the late Triassic of Poland. It was a huge predator about 5–6 metres in length and, like all rauisuchians, was equipped with a large head of long sharp teeth. The legs were placed almost underneath the body, unlike most reptiles, which would have made it quite fast and a powerful runner. The appearance was very similar to that of the more known Postosuchus, of North America, and shared with the latter the ecological niche of the apex predator.
Isalorhynchus is an extinct genus of hyperodapedontine rhynchosaur from the late Triassic period of Toliara Province, southwestern Madagascar. It is known from the holotype MDE-R18, a nearly complete maxilla and from other specimens from the same locality, Malio River area. It was found in the Makay Formation of the Morondava Basin. It was first named by Eric Buffetaut in 1983 and the type species is Isalorhynchus genovefae. The majority of Isalorhynchus specimens are isolated jaw bones, but two nearly complete skeletons were found in 1998. Langer et al., 2000 concluded that Isalorhynchus is a synonym of Hyperodapedon and referred it to a new species of Hyperodapedon. Whatley, 2005 retained this genus as valid with a description of new materials in her PhD thesis. Montefeltro et al., 2010 and Langer et al., 2010 accepted Isalorhynchus as valid genus.
Dianopachysaurus is an extinct genus of pachypleurosaur known from the lower Middle Triassic of Yunnan Province, southwestern China. It was found in the Middle Triassic Lagerstätte of the Guanling Formation. It was first named by Jun Liu, Olivier Rieppel, Da-Yong Jiang, Jonathan C. Aitchison, Ryosuke Motani, Qi-Yue Zhang, Chang-Yong Zhou and Yuan-Yuan Sun in 2011 and the type species is Dianopachysaurus dingi, thanking a Professor Ding for his help.
Stenaulorhynchus is an extinct genus of hyperodapedontid rhynchosaur known from the Middle Triassic deposits of Tanganyika Territory, Tanzania. It was found in the Lifua Member of the Manda Formation in the Karoo Supergroup. It was named and first described by Sidney Henry Haughton in 1932. The type species is Stenaulorhynchus stockleyi, a beaked herbivore measuring 1–6 meters in length.
Jesairosaurus is an extinct genus of early archosauromorph reptile known from the Illizi Province of Algeria. It is known from a single species, Jesairosaurus lehmani. Although a potential relative of the long-necked tanystropheids, this lightly-built reptile could instead be characterized by its relatively short neck as well as various skull features.
Nundasuchus is an extinct genus of crurotarsan, possibly a suchian archosaur related to Paracrocodylomorpha. Remains of this genus are known from the Middle Triassic Manda beds of southwestern Tanzania. It contains a single species, Nundasuchus songeaensis, known from a single partially complete skeleton, including vertebrae, limb elements, osteoderms, and skull fragments.
Scutarx is an extinct genus of Aetosauriformes, most commonly regarded by its species name Scutarx deltatylus. Scutarx lived around 230 million years ago during the Carnian and Norian stage of the Late Triassic. Scutarx are “medium sized” paramedian osteoderms belonging to the clade Aetosauria, a heavily armored and more herbivorous cousin of crocodiles.
Boreopricea is an extinct genus of archosauromorph reptile from the Early Triassic of arctic Russia. It is known from a fairly complete skeleton discovered in a borehole on Kolguyev Island, though damage to the specimen and loss of certain bones has complicated study of the genus. Boreopricea shared many similarities with various other archosauromorphs, making its classification controversial. Various studies have considered it a close relative of Prolacerta, tanystropheids, both, or neither. Boreopricea is unique among early archosauromorphs due to possessing contact between the jugal and squamosal bones at the rear half of the skull.
Polymorphodon is an extinct genus of archosauriform reptile from the Middle Triassic of Germany. The only known species is Polymorphodon adorfi, discovered in Lower Keuper deposits at a quarry in Eschenau, Germany. Polymorphodon is notable for its heterodont dentition, with long and conical premaxillary teeth followed by thin maxillary teeth with large serrations. Maxillary teeth near the back of the mouth are short and leaf-shaped, similar to some living and extinct reptiles with a herbivorous or omnivorous diet. This may suggest that Polymorphodon had some reliance on plants in its diet, a rarity among basal archosauriforms, most of which are carnivores.