Skeletal Anatomy of<i>Acaenasuchus Geoffreyi</i>Long and Murry, 1995 (Archosauria: Pseudosuchia) and its Implications for the Origin of the Aetosaurian Carapace

Marsh, Adam D.; Smith, Matthew E.; Parker, William G.; Irmis, Randall B.; Kligman, Ben T.

doi:10.1080/02724634.2020.1794885

Cited by 15 publications

(56 citation statements)

References 141 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another shared feature between MCN-PV 2347 and UFSM 11505 is the presence of a marked ridge that runs longitudinally (confluent with the maxilla), dividing the main body of the jugal into laterodorsal and lateroventral faces (Figures 4 and 7A: r). This ridge is also present in phytosaurs (Stocker et al, 2017), gracilisuchids (e.g., MCZ 4117), paracrocodylomorphs (e.g., Prestosuchus chiniquensis Huene 1938;Mastrantonio et al, 2019; Dromicosuchus grallator Sues et al, 2003), erpetosuchids (e.g., Maisch et al, 2013;Ezcurra et al, 2017;Lacerda et al, 2018;Foffa et al, 2020), Acaenasuchus geoffroyi (see Marsh et al, 2020), and in several aetosaurs, such as Longosuchus meadei (TMM 31185-84), Desmatosuchus spurensis (UMMP V7476), Aetosaurus ferratus (SMNS 5770 S-16), Stenomyti huangae (according to Small and Martz, 2013), Coahomasuchus chathamensis (NCSM 23618), and Coahomasuchus kahleorum Heckert and Lucas, 1999 (NMMNH P-18496). This ridge is not prominent in some aetosaurs, such as Paratypothorax andressorum (SMNS 19003;Schoch and Desojo, 2016) and Typothorax coccinarum (PEFO 38001; Reyes et al, 2021), and is absent in ornithosuchids (von Baczko and Desojo, 2016).…”

Section: ) or Stagonolepis Olenkaementioning

confidence: 99%

“…They appear to be absent in the aetosaurine Coahomasuchus chathamensis (NCSM 23618) and in the desmatosuchines Desmatosuchus spurensis (UMMP V7476) and Desmatosuchus smalli (TTUP 9024), but better preserved materials are needed to confirm this. The jugal surface is devoid of the prominent ornamentation found in some aetosaurs (e.g., P. andressorum, SMNS 19003), Acaenasuchus geoffreyi (Marsh et al, 2020), and erpetosuchids (Ezcurra et al, 2017).…”

Section: ) or Stagonolepis Olenkaementioning

confidence: 99%

“…Recent research on A. scagliai has provided a better understanding of its intraspecific variation Taborda et al, 2013;Taborda et al, 2015;Paes Neto et al, 2021b) and cranial osteology (Brust et al, 2018;Paes Neto et al, 2021a). These and other studies (e.g., Desojo, 2005) have firmly established the Gondwanan A. scagliai as a valid taxon, distinct from the Laurasian S. robertsoni and Calyptosuchus wellesi Ballew, 1985 (contra Heckert andLucas, 2000;Lucas and Heckert, 2001;Heckert and Lucas, 2002), a status recognized in most recent work on the group (e.g., Desojo et al, 2012Desojo et al, , 2013Robertoda-Silva et al, 2014;Heckert et al, 2015;Parker, 2016a,b;Schoch and Desojo, 2016;Ezcurra et al, 2017;Brust et al, 2018;Hoffman et al, 2018;Parker, 2018a,b;Desojo et al, 2020a,b;Marsh et al, 2020;Czepiński et al, 2021;Reyes et al, 2021).…”

Section: Introductionmentioning

confidence: 98%

“…Although there is consensus about their monophyly, their phylogenetic position relative to other pseudosuchians is still debatable. Recent discoveries indicate that the historically poorly-known taxon Revueltosaurus Hunt, 1989 (and its possible relatives Acaenasuchus and Euscolosuchus), from the Carnian-Norian of the United States, represents the sister-taxon of Aetosauria (Nesbitt, 2011;Nesbitt et al, 2017;Marsh et al, 2020). However, the relationship between this Revueltosaurus-aetosaur clade and others on the crocodilian stem remains poorly resolved.…”

Section: Introductionmentioning

confidence: 99%

“…However, the relationship between this Revueltosaurus-aetosaur clade and others on the crocodilian stem remains poorly resolved. Early cladistic studies tended to recover aetosaurs as closely related to Crocodylomorpha (Parrish, 1994;Gower and Walker, 1996;Brusatte et al, 2010), but more recent analyses generally recover this clade either near the base of Pseudosuchia (Nesbitt, 2011;Butler et al, 2014;Ezcurra, 2016;Lacerda et al, 2018;Desojo et al, 2020b;Foffa et al, 2020) or as part of a larger clade with the enigmatic erpetosuchids (Ezcurra et al, 2017;Nesbitt et al, 2017;Müller et al, 2020;Marsh et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Skull osteology of Aetosauroides scagliai Casamiquela, 1960 (Archosauria: Aetosauria) from the Late Triassic of Brazil: New insights into the paleobiology of aetosaurs

Neto

Desojo²,

Brust³

et al. 2021

Palaeontol Electron

View full text Add to dashboard Cite

Aetosauroides scagliai, from the Ischigualasto Formation of Argentina and Santa Maria Supersequence of Brazil (Carnian-Norian), is one of the oldest members of Aetosauria, a diverse clade of armored crocodile-line archosaurs. Aetosauroides scagliai differs from other aetosaurs in having the maxilla excluded from the margin of the external nares, the length/width ratio of the postzygapophyses ≤ 0.75, and other features that place it as one of the earliest-diverging members of the clade. In this paper we provide a detailed description of the skull of A. scagliai based on a new Brazilian specimen, revealing that it lacks a pneumatic cavity on the medial surface of the maxilla and further differs from all other known aetosaurs by the presence of ≥ 12 dentary teeth. However, contra previous studies, the elongated posterior process of the jugal does articulate ventrally with the quadratojugal in A. scagliai, forming the posteroventral corner of the skull as in all other aetosaurs. Aetosauroides scagliai exhibits some characters typical of predatory archosaurs (like the recurved ziphodont teeth and mandibular articulation at the level of the tooth row), but was probably an omnivore, as it also shares several probable adaptations for herbivory with aetosaurs generally (i.e., edentulous anterior premaxilla and dentary) and stagonolepidoids specifically (e.g., shovel-shaped snout). This suggests that there was greater trophic diversity in this clade than usually recognized, at least early in their evolutionary history.

show abstract

Section: ) or Stagonolepis Olenkaementioning

confidence: 99%

Section: ) or Stagonolepis Olenkaementioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Skull osteology of Aetosauroides scagliai Casamiquela, 1960 (Archosauria: Aetosauria) from the Late Triassic of Brazil: New insights into the paleobiology of aetosaurs

Neto

Desojo²,

Brust³

et al. 2021

Palaeontol Electron

View full text Add to dashboard Cite

show abstract

Osteology and relationships of Revueltosaurus callenderi (Archosauria: Suchia) from the Upper Triassic (Norian) Chinle Formation of Petrified Forest National Park, Arizona, United States

Parker

Nesbitt

Irmis

et al. 2021

The Anatomical Record

Self Cite

View full text Add to dashboard Cite

Once known solely from dental material and thought to represent an early ornithischian dinosaur, the early‐diverging pseudosuchian Revueltosaurus callenderi is described from a minimum of 12 skeletons from a monodominant bonebed in the upper part of the Chinle Formation of Arizona. This material includes nearly the entire skeleton and possesses a combination of plesiomorphic and derived character states that help clarify ingroup relationships within Pseudosuchia. A phylogenetic analysis recovers R. callenderi in a clade with Aetosauria and Acaenasuchus geoffreyi that is named Aetosauriformes. Key autapomorphies of R. callenderi include a skull that is longer than the femur, a complete carapace of dermal armor including paramedian and lateral rows, as well as ventral osteoderms, and a tail end sheathed in bone. Histology of the femur and associated osteoderms demonstrate that R. callenderi was slow growing and that the individuals from the bonebed were not young juveniles but had not ceased growing. A review of other material assigned to Revueltosaurus concludes that the genus cannot be adequately diagnosed based on the type materials of the three assigned species and that only R. callenderi can be confidently referred to Revueltosaurus.

show abstract

Incongruent ontogenetic maturity indicators in a Late Triassic archosaur (Aetosauria: Typothorax coccinarum)

Parker,

Reyes,

Marsh

2023

The Anatomical Record

Self Cite

View full text Add to dashboard Cite

Maximum individual body size in pseudosuchian archosaurs is not well constrained in the fossil record, but it may be influenced by a variety of factors including basal metabolic rate, evolutionary relationships, and environmental conditions. Body size varies among the Aetosauria in which estimated total length ranges between 1 m (e.g., Coahomasuchus kahleorum) and 5 m (e.g., Desmatosuchus spurensis). A new, very large specimen of the aetosaurian Typothorax coccinarum from Petrified Forest National Park in northeastern Arizona is nearly twice the size of all other known specimens of Typothorax and is the largest aetosaur specimen currently known worldwide. The specimen lacks co‐ossified neurocentral sutures in the trunk vertebrae which may suggest that the individual had not yet reached skeletal maturity, yet smaller specimens of T. coccinarum exhibit partially or fully co‐ossified neurocentral sutures in the same region. If body size correlates with skeletal maturity in aetosaurs, this discrepancy warns that timing of neurocentral suture co‐ossification in aetosaurs may not be a reliable indicator of ontogenetic stage. Osteohistological observations of a trunk rib demonstrate that although PEFO 42506 shows a large body size, the specimen did not deposit an external fundamental system despite depositing as many as 19 growth lines, further indicating that it had not yet reached skeletal maturity. Thus, at least within Aetosauria, neurocentral suture co‐ossification and skeletal maturity may correlate, whereas body size can be incongruent in comparison. Furthermore, this specimen indicates that non‐desmatosuchin aetosaurs could exhibit large body sizes and suggests that some aetosaurs may have experienced indeterminate growth.

show abstract

Skeletal Anatomy ofAcaenasuchus GeoffreyiLong and Murry, 1995 (Archosauria: Pseudosuchia) and its Implications for the Origin of the Aetosaurian Carapace

Cited by 15 publications

References 141 publications

Skull osteology of Aetosauroides scagliai Casamiquela, 1960 (Archosauria: Aetosauria) from the Late Triassic of Brazil: New insights into the paleobiology of aetosaurs

Skull osteology of Aetosauroides scagliai Casamiquela, 1960 (Archosauria: Aetosauria) from the Late Triassic of Brazil: New insights into the paleobiology of aetosaurs

Osteology and relationships of Revueltosaurus callenderi (Archosauria: Suchia) from the Upper Triassic (Norian) Chinle Formation of Petrified Forest National Park, Arizona, United States

Incongruent ontogenetic maturity indicators in a Late Triassic archosaur (Aetosauria: Typothorax coccinarum)

Contact Info

Product

Resources

About