Project 4610: D. Foffa, S. J. Nesbitt, B. T. Kligman, R. J. Butler, M. R. Stocker. 2023. New specimen and redescription of Anisodontosaurus greeri (Moenkopi Formation: Middle Triassic) and the spatiotemporal origins of Trilophosauridae. Journal of Vertebrate Paleontology. epub ahead of print:e2220015.
Abstract
Anisodontosaurus greeri is an enigmatic small-bodied heterodont tetrapod from the Holbrook Member of the Moenkopi Formation (Middle Triassic) of Arizona (USA). The evolutionary relationships of this taxon have long been debated and remain uncertain. Using micro-computed tomography (µCT) scans we redescribe the holotype of Anisodontosaurus greeri (UCMP 37804), as well as an additional specimen (MNA.V.1478) that had been informally referred to this taxon. Our new data reveal hidden details of the dentition (i.e., ankylothecodonty and absence of replacement teeth) that, in combination with the tricuspid and mediolaterally expanded crowns, support a referral of both specimens to the archosauromorph clade Trilophosauridae. The referral of MNA.V.1478 to Anisodontosaurus greeri is supported by the unique anatomy of the highly differentiated dentition (i.e., ‘figure of 8’-shaped premolariforms in occlusal views; mesiodistally short tooth row; presence of a distal ‘molariform’ crown). Comparisons of Anisodontosaurus greeri with other trilophosaurids highlights marked similarities with Variodens inopinatus from the Upper Triassic deposits of the UK. Our cladistic analyses confirm these observations, and recover, for the first time, two distinct lineages within Trilophosauridae: one geologically long-lived comprising Anisodontosaurus and Variodens; and one comprising Tricuspisaurus, Trilophosaurus spp., and Spinosuchus. These results imply that: (i) Anisodontosaurus is one of the the oldest known trilophosaurid worldwide and the oldest in North America; (ii) trilophosaurids achieved broad distribution including at low latitudes within western Pangea soon after their origins; (iii) small-body sizes were more common than previously thought among trilophosaurids.Read the article »
Article DOI: 10.1080/02724634.2023.2220015
Project DOI: 10.7934/P4610, http://dx.doi.org/10.7934/P4610
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 5123 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 235 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 496 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:224/11 |
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MorphoBank Project 4610
MorphoBank Project 4610
- Creation Date:
29 March 2023 - Publication Date:
17 July 2023 - Project views: 2789
- Matrix downloads: 1
Authors' Institutions
- University of Birmingham
- Virginia Tech (Virginia Polytechnic Institute and State University)
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Davide Foffa Project Administrator | 37 | 1 | 1 | 235 | 0 | 0 | 5123 (5123, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29215' (37 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Youngina capensis Last Modified in 07/17/23 | 49 | 186 | 186 | 0 | 0 | 0 | 0 | 1 |
[2] † Gephyrosaurus bridensis Last Modified in 07/17/23 | 64 | 171 | 171 | 0 | 0 | 0 | 0 | 1 |
[3] † Shinisaurus crocodilurus Last Modified in 07/17/23 | 27 | 208 | 208 | 0 | 0 | 0 | 0 | 1 |
[4] † Uromastyx sp Last Modified in 07/17/23 | 38 | 197 | 197 | 0 | 0 | 0 | 0 | 1 |
[5] † Protorosaurus speneri Last Modified in 07/17/23 | 65 | 170 | 170 | 0 | 0 | 0 | 0 | 1 |
[6] † Langobardisaurus pandolfii Last Modified in 07/17/23 | 130 | 105 | 105 | 0 | 0 | 0 | 0 | 1 |
[7] † Tanystropheus longobardicus Last Modified in 07/17/23 | 30 | 206 | 205 | 0 | 0 | 0 | 0 | 1 |
[8] † Tanytrachelos ahynis Last Modified in 07/17/23 | 91 | 144 | 144 | 0 | 0 | 0 | 0 | 1 |
[9] † Macrocnemus basanii Last Modified in 07/17/23 | 57 | 178 | 178 | 0 | 0 | 0 | 0 | 1 |
[10] † Amotosaurus rotfeldensis Last Modified in 07/17/23 | 166 | 69 | 69 | 0 | 0 | 0 | 0 | 1 |
[11] † Mesosuchus browni Last Modified in 07/17/23 | 27 | 209 | 208 | 0 | 0 | 0 | 0 | 1 |
[12] † Rhynchosaurus articeps Last Modified in 07/17/23 | 53 | 182 | 182 | 0 | 0 | 0 | 0 | 1 |
[13] † Teyumbaita sulcognathus Last Modified in 07/17/23 | 92 | 143 | 143 | 0 | 0 | 0 | 0 | 1 |
[14] † Pamelaria dolichotrachela Last Modified in 07/17/23 | 100 | 135 | 135 | 0 | 0 | 0 | 0 | 1 |
[15] † Azendohsaurus madagaskarensis Last Modified in 07/17/23 | 16 | 220 | 219 | 0 | 0 | 0 | 0 | 1 |
[16] † Azendohsaurus laarousii Last Modified in 07/17/23 | 203 | 32 | 32 | 0 | 0 | 0 | 0 | 1 |
[17] † Trilophosaurus buettneri Last Modified in 07/17/23 | 18 | 217 | 217 | 0 | 0 | 0 | 0 | 1 |
[18] † Trilophosaurus jacobsi Last Modified in 07/17/23 | 106 | 129 | 129 | 0 | 0 | 0 | 0 | 1 |
[19] † Teraterpeton hrynewichorum Last Modified in 07/17/23 | 124 | 111 | 111 | 0 | 0 | 0 | 0 | 1 |
[20] † Prolacerta broomi Last Modified in 07/17/23 | 22 | 215 | 213 | 0 | 0 | 0 | 0 | 1 |
[21] † Petrolacosaurus kansensis Last Modified in 07/17/23 | 31 | 204 | 204 | 0 | 0 | 0 | 0 | 1 |
[22] † Chasmatosaurus yuani Last Modified in 07/17/23 | 75 | 160 | 160 | 0 | 0 | 0 | 0 | 1 |
[23] † Proterosuchus sp Last Modified in 07/17/23 | 26 | 209 | 209 | 0 | 0 | 0 | 0 | 1 |
[24] † Proterosuchus fergusi Last Modified in 07/17/23 | 62 | 173 | 173 | 0 | 0 | 0 | 0 | 1 |
[25] † Erythrosuchus africanus Last Modified in 07/17/23 | 41 | 194 | 194 | 0 | 0 | 0 | 0 | 1 |
[26] † Euparkeria capensis Last Modified in 07/17/23 | 45 | 190 | 190 | 0 | 0 | 0 | 0 | 1 |
[27] † Batrachotomus kupferzellensis Last Modified in 07/17/23 | 42 | 194 | 193 | 0 | 0 | 0 | 0 | 1 |
[28] † Coelophysis bauri Last Modified in 07/17/23 | 38 | 198 | 197 | 0 | 0 | 0 | 0 | 1 |
[29] † Plateosaurus engelhardti Last Modified in 07/17/23 | 31 | 205 | 204 | 0 | 0 | 0 | 0 | 1 |
[30] † Tricuspisaurus thomasi Last Modified in 07/17/23 | 209 | 26 | 26 | 0 | 0 | 0 | 0 | 1 |
[31] † Trilophosaurus phasmalophos Last Modified in 07/17/23 | 226 | 9 | 9 | 0 | 0 | 0 | 0 | 1 |
[32] † Trilophosaurus dornorum Last Modified in 07/17/23 | 216 | 19 | 19 | 0 | 0 | 0 | 0 | 1 |
[33] † Variodens inopinatus Last Modified in 07/17/23 | 210 | 28 | 25 | 0 | 0 | 0 | 0 | 1 |
[34] † Spinosuchus caseanus Last Modified in 07/17/23 | 208 | 27 | 27 | 0 | 0 | 0 | 0 | 1 |
[35] † Anisodontosaurus greeri Last Modified in 07/17/23 | 212 | 24 | 23 | 0 | 0 | 0 | 0 | 1 |
[36] † Anisodontosaurus greeri UCMP Last Modified in 07/17/23 | 217 | 18 | 18 | 0 | 0 | 0 | 0 | 1 |
[37] † Anisodontosaurus greeri MNA Last Modified in 07/17/23 | 218 | 18 | 17 | 0 | 0 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 2789 | |
Project overview | 200 | |
Matrix views | 137 | Matrix landing page (129 views); Foffa et al. 2023 (8 views); |
Taxon list | 1229 | |
Documents list | 129 | |
Bibliography | 97 | |
Media views | 560 | Media search (470 views); M890363 (90 views); |
Views for media list | 162 | |
Specimen list | 275 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 3 | |
Document downloads | 2 | TNT analyses (1 download); MrBayes analyses (1 download); |
Matrix downloads | 1 | Foffa et al. 2023 (1 download); |