Project 198: S. J. Nesbitt. 2011. The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades. Bulletin of the American Museum of Natural History. 352:1-292.
Abstract
Archosaurs have a nearly 250 million year record that originated shortly after the Permian-Triassic extinction event and is continued today by two extant clades, the crocodylians and the avians. The two extant lineages exemplify two bauplan extremes among a diverse and complex evolutionary history, but little is known about the common ancestor of these lineages. Renewed interest in early archosaurs has led to nearly a doubling of the known taxa in the last20 years. This study presents a thorough phylogenetic analysis of 80 species-level taxa ranging from the latest Permian to the early part of the Jurassic using a dataset of 412 characters. Each terminal taxon is explicitly described and all specimens used in the analysis are clearly stated.Additionally, each character is discussed in detail and nearly all of the character states are illustrated in either a drawing or highlighted on a specimen photograph. A combination of novel characters and comprehensive character sampling has bridged previously published analyses that focus on particular archosauriform subclades.
A well-resolved, robustly supported consensus tree (MPTs 360) found a monophyletic Archosauria consisting of two major branches, the crocodylian-line and avian-line lineages. The monophyly of clades such as Ornithosuchidae, Phytosauria, Aetosauria, Crocodylomorpha, and Dinosauria is supported in this analysis. However, phytosaurs are recovered as the closest sister taxon to Archosauria, rather than basal crocodylian-line archosaurs, for the first time. Among taxa classically termed as ‘‘rauisuchians,’’ a monophyletic poposauroid clade was found as the sister taxon to a group of paraphyletic ‘‘rauisuchians’’ and monophyletic crocodylomorphs. Hence, crocodylomorphs are well nested within a clade of ‘‘rauisuchians,’’ and are not more closely related to aetosaurs than to taxa such as Postosuchus. Basal crocodylomorphs such as Hesperosuchus and similar forms (‘‘Sphenosuchia’’) were found as a paraphyletic grade leading to the clade Crocodyliformes. Among avian-line archosaurs, Dinosauria is well supported. A monophyletic clade containing Silesaurus and similar forms is well supported as the sister taxon to Dinosauria. Pterosaurs are robustly supported at the base of the avian line.
A time-calibrated phylogeny of Archosauriformes indicates that the origin and initial diversification of Archosauria occurred during the Early Triassic following the Permian-Triassic extinction. Furthermore, all major basal archosaur lineages except Crocodylomorpha were established by the end of the Anisian. Early archosaur evolution is characterized by high rates of homoplasy, long ghost lineages, and high rates of character evolution. These data imply that much of the early history of Archosauria has not been recovered from the fossil record. Not only were archosaurs diverse by the Middle Triassic, but they had nearly a cosmopolitan biogeographic distribution by the end of the Anisian.
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Project DOI: 10.7934/P198, http://dx.doi.org/10.7934/P198
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 29317 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 412 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 895 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:412/0 |
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MorphoBank Project 198
MorphoBank Project 198
- Creation Date:
07 March 2008 - Publication Date:
04 May 2011 - Project views: 69113
- Media downloads: 2
- Matrix downloads: 267
This research
supported by
Authors' Institutions
- American Museum of Natural History
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Sterling Nesbitt Project Administrator | 151 | 0 | 0 | 412 | 0 | 0 | 29317 (20455, 7745, 1117) | 0 | 0 | 0 | ||||
MorphoBank Curator Full membership | 0 | 1 | 0 | 0 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 | ||||
Randall Irmis Full membership | 0 | 0 | 0 | 0 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 | ||||
Mark Norell Full membership | 0 | 0 | 0 | 0 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M559' (83 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Mesosuchus browni Last Modified in 12/05/13 | 21 | 330 | 330 | 14 | 47 | 0 | 0 | 4 |
[2] † Prolacerta broomi Last Modified in 12/05/13 | 9 | 358 | 356 | 4 | 41 | 0 | 0 | 4 |
[3] † Archosaurus rossicus Last Modified in 12/05/13 | 407 | 5 | 5 | 0 | 0 | 0 | 0 | 4 |
[4] † Proterosuchus fergusi Last Modified in 12/05/13 | 4 | 363 | 360 | 15 | 30 | 0 | 0 | 4 |
[5] † Erythrosuchus africanus Last Modified in 12/05/13 | 7 | 362 | 362 | 20 | 23 | 0 | 0 | 4 |
[6] † Vancleavea campi Last Modified in 12/05/13 | 102 | 281 | 281 | 5 | 24 | 0 | 0 | 4 |
[7] † Chanaresuchus bonapartei Last Modified in 12/05/13 | 15 | 359 | 359 | 26 | 12 | 0 | 0 | 4 |
[8] † Tropidosuchus romeri Last Modified in 12/05/13 | 35 | 310 | 310 | 53 | 14 | 0 | 0 | 4 |
[9] † Euparkeria capensis Last Modified in 12/05/13 | 6 | 395 | 394 | 3 | 9 | 0 | 0 | 4 |
[10] † Parasuchus hislopi Last Modified in 12/05/13 | 53 | 346 | 346 | 1 | 12 | 0 | 0 | 4 |
[11] † Smilosuchus gregorii Last Modified in 12/05/13 | 32 | 337 | 337 | 29 | 14 | 0 | 0 | 4 |
[12] † Pseudopalatus pristinus Last Modified in 12/05/13 | 18 | 381 | 381 | 1 | 12 | 0 | 0 | 4 |
[13] † Gracilisuchus stipanicicorum Last Modified in 12/05/13 | 27 | 302 | 302 | 74 | 9 | 0 | 0 | 4 |
[14] † Turfanosuchus dabanensis Last Modified in 12/05/13 | 22 | 260 | 258 | 123 | 7 | 0 | 0 | 4 |
[15] † Ornithosuchus longidens Last Modified in 12/05/13 | 80 | 272 | 272 | 53 | 7 | 0 | 0 | 4 |
[16] † Riojasuchus tenuisceps Last Modified in 12/05/13 | 27 | 351 | 351 | 25 | 9 | 0 | 0 | 4 |
[17] † Revueltosaurus callenderi Last Modified in 12/05/13 | 39 | 366 | 366 | 1 | 6 | 0 | 0 | 4 |
[18] † Stagonolepis robertsoni Last Modified in 12/05/13 | 94 | 312 | 311 | 2 | 4 | 0 | 0 | 4 |
[19] † Aetosaurus ferratus Last Modified in 12/05/13 | 115 | 265 | 264 | 31 | 2 | 0 | 0 | 4 |
[20] † Longosuchus meadei Last Modified in 12/05/13 | 56 | 343 | 332 | 6 | 7 | 0 | 0 | 4 |
[21] † Ticinosuchus ferox Last Modified in 12/05/13 | 196 | 201 | 196 | 11 | 4 | 0 | 0 | 4 |
[22] † Qianosuchus mixtus Last Modified in 12/05/13 | 99 | 281 | 281 | 29 | 3 | 0 | 0 | 4 |
[23] † Xilousuchus sapingensis Last Modified in 12/05/13 | 7 | 117 | 116 | 288 | 0 | 0 | 0 | 4 |
[24] † Arizonasaurus babbitti Last Modified in 12/05/13 | 24 | 252 | 250 | 124 | 12 | 0 | 0 | 4 |
[25] † Poposaurus gracilis holotype Last Modified in 12/05/13 | 9 | 38 | 37 | 364 | 1 | 0 | 0 | 4 |
[26] † Poposaurus gracilis yale Last Modified in 12/05/13 | 22 | 213 | 207 | 164 | 14 | 0 | 0 | 4 |
[27] † Lotosaurus adentus Last Modified in 12/05/13 | 40 | 309 | 309 | 33 | 30 | 0 | 0 | 4 |
[28] † Sillosuchus longicervix Last Modified in 12/05/13 | 47 | 78 | 78 | 277 | 10 | 0 | 0 | 4 |
[29] † Effigia okeeffeae Last Modified in 12/05/13 | 43 | 314 | 314 | 26 | 29 | 0 | 0 | 4 |
[30] † Shuvosaurus inexpectatus Last Modified in 12/05/13 | 44 | 307 | 307 | 32 | 29 | 0 | 0 | 4 |
[31] † Prestosuchus chiniquensis Last Modified in 12/05/13 | 21 | 169 | 169 | 220 | 2 | 0 | 0 | 4 |
[32] † UFRGS 0156-T Last Modified in 12/05/13 | 42 | 166 | 166 | 202 | 2 | 0 | 0 | 4 |
[33] † UFRGS 152-T Last Modified in 12/05/13 | 35 | 264 | 264 | 110 | 3 | 0 | 0 | 4 |
[34] Combined Prestosuchus Last Modified in 12/05/13 | 54 | 352 | 352 | 2 | 4 | 0 | 0 | 4 |
[35] † Saurosuchus galilei Last Modified in 12/05/13 | 48 | 308 | 303 | 54 | 2 | 0 | 0 | 4 |
[36] † Batrachotomus kuperferzellensis Last Modified in 12/05/13 | 7 | 349 | 345 | 55 | 1 | 0 | 0 | 4 |
[37] † Fasolasuchus tenax Last Modified in 12/05/13 | 4 | 161 | 161 | 245 | 2 | 0 | 0 | 4 |
[38] † Rauisuchus triradentes Last Modified in 12/05/13 | 17 | 132 | 132 | 263 | 0 | 0 | 0 | 4 |
[39] † Polonosuchus silesiacus Last Modified in 12/05/13 | 7 | 118 | 118 | 287 | 0 | 0 | 0 | 4 |
[40] † Postosuchus kirkpatricki Last Modified in 12/05/13 | 37 | 336 | 336 | 35 | 4 | 0 | 0 | 4 |
[41] † Postosuchus alisonae Last Modified in 12/05/13 | 9 | 168 | 167 | 233 | 2 | 0 | 0 | 4 |
[42] † CM 73372 Last Modified in 12/05/13 | 53 | 161 | 160 | 194 | 4 | 0 | 0 | 4 |
[43] † Hesperosuchus agilis Last Modified in 12/05/13 | 10 | 214 | 213 | 185 | 3 | 0 | 0 | 4 |
[44] † Dromicosuchus grallator Last Modified in 12/05/13 | 72 | 269 | 268 | 67 | 4 | 0 | 0 | 4 |
[45] † Hesperosuchus "agilis" Last Modified in 12/05/13 | 19 | 288 | 288 | 100 | 5 | 0 | 0 | 4 |
[46] † Dibothrosuchus elaphros Last Modified in 12/05/13 | 160 | 217 | 217 | 29 | 6 | 0 | 0 | 4 |
[47] † Terrestrisuchus gracilis Last Modified in 12/05/13 | 63 | 316 | 316 | 25 | 8 | 0 | 0 | 4 |
[48] † Sphenosuchus acutus Last Modified in 12/05/13 | 13 | 215 | 214 | 179 | 5 | 0 | 0 | 4 |
[49] † Litargosuchus leptorhynchus Last Modified in 12/05/13 | 12 | 189 | 188 | 208 | 3 | 0 | 0 | 4 |
[50] † Kayentasuchus walkeri Last Modified in 12/05/13 | 280 | 106 | 106 | 24 | 2 | 0 | 0 | 4 |
[51] † Orthosuchus stormbergi Last Modified in 12/05/13 | 72 | 320 | 320 | 6 | 14 | 0 | 0 | 4 |
[52] Alligator mississippiensis Last Modified in 12/05/13 | 4 | 369 | 366 | 0 | 41 | 0 | 0 | 4 |
[53] † Protosuchus haughtoni Last Modified in 12/05/13 | 8 | 158 | 158 | 241 | 5 | 0 | 0 | 4 |
[54] † Protosuchus richardsoni Last Modified in 12/05/13 | 32 | 359 | 359 | 9 | 12 | 0 | 0 | 4 |
[55] † Eudimorphodon ranzii Last Modified in 12/05/13 | 177 | 191 | 191 | 9 | 35 | 0 | 0 | 4 |
[56] † Dimorphodon macronyx Last Modified in 12/05/13 | 159 | 200 | 200 | 18 | 35 | 0 | 0 | 4 |
[57] † Lagerpeton chanarensis Last Modified in 12/05/13 | 7 | 133 | 133 | 252 | 20 | 0 | 0 | 4 |
[58] † Dromomeron gregorii Last Modified in 12/05/13 | 79 | 42 | 42 | 290 | 1 | 0 | 0 | 4 |
[59] † Dromomeron romeri Last Modified in 12/05/13 | 313 | 61 | 61 | 18 | 20 | 0 | 0 | 4 |
[60] † Marasuchus lilloensis Last Modified in 12/05/13 | 28 | 203 | 203 | 165 | 16 | 0 | 0 | 4 |
[61] † Asilisaurus kongwe Last Modified in 12/05/13 | 11 | 174 | 174 | 211 | 16 | 0 | 0 | 4 |
[62] † Eucoelophysis baldwini Last Modified in 12/05/13 | 117 | 26 | 26 | 269 | 0 | 0 | 0 | 4 |
[63] † Sacisaurus agudoensis Last Modified in 12/05/13 | 20 | 90 | 90 | 298 | 4 | 0 | 0 | 4 |
[64] † Lewisuchus admixtus Last Modified in 12/05/13 | 16 | 129 | 129 | 257 | 10 | 0 | 0 | 4 |
[65] † Pseudolagosuchus majori Last Modified in 12/05/13 | 39 | 95 | 95 | 261 | 17 | 0 | 0 | 4 |
[66] † Lewisuchus/Pseudolagosuchus Last Modified in 12/05/13 | 181 | 223 | 223 | 6 | 2 | 0 | 0 | 4 |
[67] † Eocursor parvus Last Modified in 12/05/13 | 14 | 140 | 140 | 245 | 13 | 0 | 0 | 4 |
[68] † Silesaurus opolensis Last Modified in 12/05/13 | 19 | 333 | 331 | 37 | 24 | 0 | 0 | 4 |
[69] † Pisanosaurus mertii Last Modified in 12/05/13 | 15 | 88 | 88 | 292 | 17 | 0 | 0 | 4 |
[70] † Heterodontosaurus tucki Last Modified in 12/05/13 | 44 | 342 | 340 | 0 | 28 | 0 | 0 | 4 |
[71] † Lesothosaurus diagnosticus Last Modified in 12/05/13 | 58 | 328 | 327 | 1 | 26 | 0 | 0 | 4 |
[72] † Scutellosaurus lawleri Last Modified in 12/05/13 | 215 | 168 | 165 | 14 | 16 | 0 | 0 | 4 |
[73] † Herrerasaurus ischigualastensis Last Modified in 12/05/13 | 45 | 343 | 340 | 1 | 23 | 0 | 0 | 4 |
[74] † Staurikosaurus pricei Last Modified in 12/05/13 | 12 | 115 | 115 | 272 | 13 | 0 | 0 | 4 |
[75] † Eoraptor lunensis Last Modified in 12/05/13 | 100 | 282 | 275 | 8 | 23 | 0 | 0 | 4 |
[76] † Saturnalia tupiniquim Last Modified in 12/05/13 | 190 | 192 | 192 | 9 | 21 | 0 | 0 | 4 |
[77] † Plateosaurus engelhardti Last Modified in 12/05/13 | 6 | 382 | 380 | 0 | 24 | 0 | 0 | 4 |
[78] † Efraasia minor Last Modified in 12/05/13 | 66 | 318 | 318 | 2 | 26 | 0 | 0 | 4 |
[79] † Tawa hallae Last Modified in 12/05/13 | 44 | 343 | 343 | 1 | 24 | 0 | 0 | 4 |
[80] † Coelophysis bauri Last Modified in 12/05/13 | 31 | 360 | 360 | 0 | 21 | 0 | 0 | 4 |
[81] † Dilophosaurus wetherelli Last Modified in 12/05/13 | 52 | 336 | 334 | 1 | 23 | 0 | 0 | 4 |
[82] † Allosaurus fragilis Last Modified in 12/05/13 | 11 | 371 | 371 | 0 | 30 | 0 | 0 | 4 |
[83] † Velociraptor mongoliensis Last Modified in 12/05/13 | 43 | 335 | 334 | 1 | 34 | 0 | 0 | 4 |
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Total downloads from project | 802 | |
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