A large archosauriform tooth with multiple supernumerary carinae from the Upper Triassic of New Mexico (USA), with comments on carina development and anomalies in the Archosauria

Beatty, Brian L.; Heckert, Andrew B.

doi:10.1080/08912960903154511

Cited by 17 publications

(8 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Enamel thickness in observed specimens shows that, like many other archosauromorphs (Sander,1999; Beatty and Heckert,2009), Dakosaurus enamel remained thin despite the large size of the teeth. This restricts microwear studies largely to the dentine surface.…”

Section: Resultsmentioning

confidence: 56%

Tooth‐On‐Tooth Interlocking Occlusion Suggests Macrophagy in the Mesozoic Marine Crocodylomorph Dakosaurus

Young

Brusatte

Beatty

et al. 2012

The Anatomical Record

View full text Add to dashboard Cite

Metriorhynchidae was a peculiar but long-lived group of marine Mesozoic crocodylomorphs adapted to a pelagic lifestyle. Recent discoveries show that metriorhynchids evolved a wide range of craniodental morphotypes and inferred feeding strategies. One genus, Dakosaurus, is arguably the most aberrant marine crocodylomorph due to its large, robust, ziphodont teeth; very low tooth count; and brevirostrine/oreinirostral snout. We here report an additional unusual feature of Dakosaurus that is unique among marine crocodylomorphs: tightly fitting tooth-totooth occlusion, whose inference is supported by reception pits along the upper and lower tooth rows, indicative of vertically orientated crowns that were in close contact during occlusion, and three distinct types of dental wear. These include irregular spalled surfaces near the apex (probably caused by tooth-food contact), semi-circular wear near the base, and elongate surfaces extending along the mesial and distal margins of the teeth, obliterating the carinae (including the denticles). Scanning electron micrographs show that these latter surfaces are marked by parallel apicobasal striations, which in extant mammals reflect tooth-tooth contact. As such, we interpret the carinal wear facets in Dakosaurus as being formed by repeated tooth-tooth contact

show abstract

Section: Resultsmentioning

confidence: 56%

Tooth‐On‐Tooth Interlocking Occlusion Suggests Macrophagy in the Mesozoic Marine Crocodylomorph Dakosaurus

Young

Brusatte

Beatty

et al. 2012

The Anatomical Record

View full text Add to dashboard Cite

show abstract

“…These differences are substantial, and similar to the way in which enamel thickness has been observed to change from thin at the base to thicker near the apex in some archosauromorphs (Beatty and Heckert 2009) and squamates (Pellegrini and Beatty 2011) that lack surface ornamentation. Interestingly, a Kimmeridgian Machimosaurus tooth from England also shows this substantial difference in enamel thickness (Young and Steel 2014).…”

Section: Descriptionmentioning

confidence: 59%

First evidence of denticulated dentition in teleosaurid crocodylomorphs

Young¹,

Beatty²,

Brusatte³

et al. 2013

APP

View full text Add to dashboard Cite

Teleosauridae was a group of largely marine Mesozoic crocodylomorphs, typically considered as akin to "marine gavials" due to their elongate, tubular, polydont rostra that are indicative of a piscivorous diet. Here we show that these extinct crocodylomorphs were more anatomically, and perhaps ecologically, varied than previously thought. We report the first evidence of denticles in a teleosaurid tooth, revealed by scanning electron microscopic (SEM) analysis of a tooth from the holotype of "Steneosaurus" obtusidens. These denticles are cryptic, because they are microscopic, not contiguous along the carinae (instead forming short series), and are detectable only using SEM. This incipient denticle morphology is similar to that recently discovered in a closely related group of marine crocodylomorphs, the Metriorhynchidae. In particular, the denticulation morphology of "Steneosaurus " is similar to that of the geosaurin metriorhynchid Torvoneustes, indicating that these two taxa may have employed similar feeding styles and that "S."obtusidens may have been a nearshore ecological analogue to the more offshore, fast-swimming geosaurins. Previous authors have considered "S." obtusidens and Machimosaurus to be durophagous, but the discovery of denticulated teeth indicates that they had a more varied diet and feeding style, and included flesh slicing as part of their feeding toolkit. It is currently unknown how extensive denticulate carinae may be in Teleosauridae, and we hypothesise that cryptic denticles may also be present in other marine crocodylomorphs once they are subjected to SEM study.

show abstract

“…(2007) considered ‘ornithischian’ taxa such as Crosbysaurus (reported by Heckert 2004) as valid taxa, but diagnostic only of Archosauriformes incertae sedis . More recently, Beatty and Heckert (2009) documented a large, pathological archosauriform tooth that could pertain to a phytosaur (as suggested by Heckert 1997 a , b ), but more likely represents a rauisuchian or other large archosaur from the same stratigraphic interval.…”

Section: Geological Settingmentioning

confidence: 92%

A new species of the enigmatic archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation, New Mexico, USA

Heckert¹,

Lucas

Spielmann

2012

Palaeontology

Self Cite

View full text Add to dashboard Cite

Doswellia sixmilensis is a new species of the doswelliid archosauromorph genus Doswellia named for an incomplete skeleton from the Upper Triassic Bluewater Creek Formation of the Chinle Group in west‐central New Mexico, USA. D. sixmilensis differs from D. kaltenbachi Weems, the type and only other known species of Doswellia, in its larger size, higher tooth count and greater heterodonty, possession of keels on the cervical centra and the presence of discrete knobs or spikes on some osteoderms. The holotype of D. sixmilensis is the fourth occurrence of Doswellia and only the second occurrence of a Doswellia skull, which includes the previously unknown premaxilla and maxilla (and therefore the best dentition) and has the best‐preserved cervical vertebrae. Although it adds to our knowledge of the anatomy of Doswellia, this new information does not alter previous concepts of the phylogenetic relationships of the doswelliid genera, largely because they are so poorly known anatomically. The genus Doswellia is known from the Newark Supergroup in Virginia, and the Chinle Group in Texas, New Mexico and Utah, in strata of Otischalkian–Adamanian age. The type locality of D. sixmilensis is c. 43 m stratigraphically below a bed from which U‐Pb dating of detrital zircons yields a maximum depositional age of c. 220 Ma, so this is a reasonable approximate numerical age for D. sixmilensis.

show abstract

A large archosauriform tooth with multiple supernumerary carinae from the Upper Triassic of New Mexico (USA), with comments on carina development and anomalies in the Archosauria

Cited by 17 publications

References 63 publications

Tooth‐On‐Tooth Interlocking Occlusion Suggests Macrophagy in the Mesozoic Marine Crocodylomorph Dakosaurus

Tooth‐On‐Tooth Interlocking Occlusion Suggests Macrophagy in the Mesozoic Marine Crocodylomorph Dakosaurus

First evidence of denticulated dentition in teleosaurid crocodylomorphs

A new species of the enigmatic archosauromorph Doswellia from the Upper Triassic Bluewater Creek Formation, New Mexico, USA

Contact Info

Product

Resources

About