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Title: Garzapelta muelleri gen. et sp. nov., a new aetosaur ( Archosauria: Pseudosuchia ) from the Late Triassic (middle Norian ) middle Cooper Canyon Formation, Dockum Group, Texas, USA , and its implications on our understanding of the morphological disparity of the aetosaurian dorsal carapace
Abstract

The Late Triassic Dockum Group in northwestern Texas preserves a rich diversity of pseudosuchian taxa, particularly of aetosaurs. In this contribution, we presentGarzapelta muellerigen. et sp. nov., a new aetosaur from the Late Triassic middle Cooper Canyon Formation (latest Adamanian–earliest Revueltian teilzones) in Garza County, Texas, based on an associated specimen that preserves a significant portion of its dorsal carapace. The carapace ofG.muelleriexhibits a striking degree of similarity between that of the paratypothoracinRioarribasuchus chamaensisand desmatosuchins. We quantitatively assessed the relationships ofG.muelleriusing several iterations of the matrix. Scoring the paramedian and lateral osteoderms ofG.muelleriindependently results in conflicting topologies. Thus, it is evident that our current matrix is limited in its ability to discern the convergence within this new taxon and that our current character lists are not fully accounting for the morphological disparity of the aetosaurian carapace. Qualitative comparisons suggest thatG.muelleriis aRioarribasuchus‐like paratypothoracin with lateral osteoderms that are convergent with those of desmatosuchins. Although the shape of the dorsal eminence, and the presence of a dorsal flange that is rectangular and proportionately longer than the lateral flange are desmatosuchin‐like features ofG.muelleri, the taxon does not exhibit the articulation style between the paramedian and lateral osteoderms which diagnose the Desmatosuchini (i.e., a rigid interlocking contact, and an anteromedial edge of the lateral osteoderm that overlaps the adjacent paramedian osteoderm).

 
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NSF-PAR ID:
10485444
Author(s) / Creator(s):
 ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
The Anatomical Record
Volume:
307
Issue:
4
ISSN:
1932-8486
Format(s):
Medium: X Size: p. 1271-1299
Size(s):
p. 1271-1299
Sponsoring Org:
National Science Foundation
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