Topic
Habrosaurus
About: Habrosaurus is a research topic. Over the lifetime, 4 publications have been published within this topic receiving 82 citations. The topic is also known as: Habrosaurus prodilatus.
Papers
TL;DR: The Ellisdale site has produced the first representative fossil amphibian specimens from the Cretaceous of eastern North America, and a previously undescribed genus of batrachosauroidid salamander, herein described as Parrisia neocesariensis gen. et sp.
Abstract: The Ellisdale site (Late Cretaceous, Campanian), Monmouth County, New Jersey, has produced the first representative fossil amphibian specimens from the Cretaceous of eastern North America. The known fauna includes indeterminate pelobatid and discoglossid frogs, an amphiumid (cf. Proamphiuma sp.), and a sirenian (cf. Habrosaurus sp.), however, the most abundant caudate remains are from a previously undescribed genus of batrachosauroidid salamander, herein described as Parrisia neocesariensis gen. et sp. nov. The genus Parrisia is established as batrachosauroidid by: an atlas with deeply concave anterior cotyles; lack of a well developed atlantal intercotylar process; and a ring or dome of calcified cartilage on the opisthocoelus vertebral condyles bearing a persistent notochordal pit. It differs from the other members of the family, including Opisthotriton and Prodesmodon (Late Cretaceous, western North America) by the presence of: unossified neural spine tips; paired caudal intravertebral nerve o...
30 citations
TL;DR: The sirenid salamander Habrosaurus is revised and redescribed based on skull elements and vertebrae from the middle Campanian–middle Palaeocene of the North American Western Interior and is argued to be the geologically oldest, undoubted sirensid and the sister-taxon of Siren + Pseudobranchus.
Abstract: The sirenid salamander Habrosaurus is revised and redescribed based on skull elements and vertebrae from the middle Campanian–middle Palaeocene of the North American Western Interior. Habrosaurus differs from the Cenozoic (Eocene–Recent) sirenids Siren and Pseudobranchus in a suite of cranial and vertebral plesiomorphies, one vertebral character of uncertain polarity and five apomorphies describing the structure of the dentary, atlas and tooth crowns. Two species are identified based on dental characters: the type species H. dilatus (late Maastrichtian–middle Palaeocene) has stout marginal and palatal teeth with bulbous crowns and prominent wear facets, whereas H. prodilatus sp. nov. (middle Campanian) has chisel-like marginal teeth (palatal teeth unknown) with weaker wear facets. Habrosaurus is argued to be the geologically oldest, undoubted sirenid and the sister-taxon of Siren + Pseudobranchus. Replacement of marginal teeth with a broad, horny beak in Siren and Pseudobranchus and the broad, bulbous marginal and palatal teeth in H. dilatus are proposed to be convergent strategies for achieving a crushing bite. The chisel-like teeth of H. prodilatus are interpreted as being transitional to the more specialized, crushing dentition of H. dilatus.
26 citations
TL;DR: The dentition in the recent forms investigated is compared to that of other paedomorphic Urodela und the ancient Habrosaurus dilatus (Sirenidae).
Abstract: 1. Dentition, tooth structure and course of dental laminae of adult and subadult Sirenidae (Siren intermedia, S. lacertina, Pseudobranchus striatus) have been studied by light microscopy and scanning electron microscopy.
2. Splenials, vomers und palatines bear monocuspid unbladed teeth, arranged in a polystichous pattern, whereas praemaxillaries and maxillaries (so far as present) are edentate. Teeth in S. intermedia show a rough basis, which is more prominent in S. lacertina and which has break-throughs in P. striatus. This zone perhaps is homologous to a developing dividing zone typical for teeth in many “Lissamphibia”.
3. With respect to structure and organisation of dentigerous bones and teeth Sirenidae obviously possess a mosaicism of differently developed larval characters in their mouth cavity.
4. The dentition in the recent forms investigated is compared to that of other paedomorphic Urodela und the ancient Habrosaurus dilatus (Sirenidae).
22 citations
TL;DR: Late-early Paleocene salamanders and lizards from the Gidley and Silberling quarries comprise a rather small but relatively diverse assemblage of small amphibians and reptiles from the Western Interior of North America.
Abstract: Late-early Paleocene (Torrejonian) salamanders and lizards from the Gidley and Silberling quarries comprise a rather small but relatively diverse assemblage. Salamanders include the batrachosauroidids Opisthotriton kayi, O. gidleyi, sp. nov., the scapherpetontid Scapherpeton tectum, and the sirenid Habrosaurus dilatus. Lizards include the xantusiid Palaeoxantusia fera, the enigmatic anguids Machaerosaurus torrejonensis and Proxestops silberlingii, and an indeterminate varanid or necrosaurid. Machaerosaurus torrejonensis is better placed as Anguidae incertae sedis because it lacks any diagnostic (synapomorphic) characters that permit assignment to the “Anguinae.” Proxestops jepseni is a junior synonym of Proxestops silberlingii, comb. nov. This assemblage is similar to other Torrejonian assemblages of small amphibians and reptiles from the Western Interior of North America.
20 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2009 | 1 |
| 2003 | 1 |
| 1998 | 1 |
| 1991 | 1 |