Project 1070: C. D. Muizon, G. Billet, C. Argot, S. Ladevèze, F. Goussard. 2015. Alcidedorbignya inopinata, a basal pantodont (Placentalia, Mammalia) from the early Palaeocene of Bolivia: anatomy, phylogeny and palaeobiology. Geodiversitas. 37 (4):397.
Abstract
Alcidedorbignya inopinata Muizon & Marshall, 1987 is a basal pantodont (Placentalia, Mammalia) of small body size, from the early Palaeocene of the Santa Lucia Formation at Tiupampa, Bolivia. Tiupampa is the type locality for the Tiupampan, a South American Land Mammal age (SALMA), which is assigned an age equivalent to the basal Torrejonian 1 of North America (c. 65 Ma). Alcidedorbignya is known by exceptionally preserved specimens, which are described here. The two major specimens are an almost complete skeleton (MHNC 8372) and a partial skull (MHNC 8399), the former representing one of the best-preserved fossil placentals from the early Palaeocene and probably the oldest placental skeleton that is so completely known. These specimens are also the first eutherian skulls and skeleton ever discovered at Tiupampa, a locality which has yielded numerous metatherian skulls and partial skeletons. The remarkable preservation of the two skulls allows a detailed description of the cranial anatomy with well-identified sutures and foramina, including those of the auditory region. Through CT scanning of the skulls, the arterial and venous circulation pattern in the basicranium as well as the bony labyrinth of the inner ear were tentatively reconstructed. A thorough description of the postcranial skeleton of MHNC 8372 is also provided. Among pantodonts, Alcidedorbignya presents the closest morphological similarities with Pantolambda, the oldest and earliest diverging North American pantodont (known by skulls and skeletons), from the late early Palaeocene (Torrejonian 2 and 3) of New Mexico. Alcidedorbignya is one-third the size, much more gracile, and clearly exhibits more plesiomorphic features than Pantolambda. It is also at least 3 Ma older. Interesting similarities are also observed between the skull of Alcidedorbignya and several “condylarths”, such as Maiorana, Baioconodon, Arctocyon, and Arctocyonides. The basicranium of Alcidedorbignya is also similar to that of some extant afrotheres (e.g., Tenrec) or Lipotyphla (e.g., Solenodon), but most of these similarities may represent placental symplesiomorphies. In fact, the cranial anatomy of Alcidedorbignya, beyond the simple thorough description of a basal pantodont, sheds light on the cranial anatomy of placentals from the earliest Paleocene, previously unknown in this detail. The postcranial skeleton of MHNC 8372 together with some isolated specimens referred to A. inopinata, is compared to adequate morphofunctional models (e.g., Solenodon, Dendrohyrax, Sciurus), which indicates that it was a moderately agile, plantigrade, generalized terrestrial mammal with good climbing ability (scansorial) and occasionally capable of standing in a bipedal position. The scutiform ungual phalanges were probably bearing nail-like hooves (or primate-like nails) and because of the absence of claws, fossorial habits are unlikely.A parsimony analysis of a data matrix including 72 taxa and 426 characters (cranial and postcranial) has been undertaken with TNT and Paup 4b10. The matrix includes several stem eutherians and representatives of the four major clades of Placentalia: Laurasiatheria, Euarchontoglires, Xenarthra, and Afrotheria. Furthermore, because one of the major aims of this analysis is to test possible close phylogenetic relationships of Alcidedorbignya inopinata with the five orders of South American “ungulates”, 12 taxa belonging to the Notoungulata, Astrapotheria, Litopterna, Pyrotheria and Xenungulata, were included in the matrix. Two analyses were performed: one unconstrained and one with a backbone constraint based on the latest molecular phylogenies. One of the main results of these analyses is the high level of homoplasy detected by the low retention index (RI close to 0.5; CI inferior to 0.2), which indicates that half of the similarities present in the matrix are interpreted as homoplasies. Nevertheless, some interesting observations emerge. In both analyses, all members of Pantodonta are closely related and included in the Placentalia, and the Eocene “cimolestid” taxon Didelphodus, which has been regarded as closely related to pantodonts, is their sister-group. In the constrained analysis, the Pantodonta are monophyletic and included in the Laurasiatheria; Didelphodus and the pantodonts are clustered with the Tillodontia, either as their sister group or included in a clade also comprising some “condylarths”. In the unconstrained analysis the xenungulate Carodnia is included within the Pantodonta as the sister group of Coryphodon, this clade being part of a large basal polytomy of placental lineages. Both analyses agree with a northern origin of the South American pantodont Alcidedorbignya as it is nested within northern taxa. Furthermore, no close relationship of Alcidedorbignya with South American endemic ungulates is supported, except for pantodont-xenungulate affinities in the unconstrained analysis. In the constrained analysis the five groups of South American endemic “ungulates” are gathered in a single clade included in the laurasiatheres but not directly related to pantodonts. Finally, the rather apical position of Alcidedorbignya in both analyses may be considered as an argument for a pre-K-Pg placental diversification, as this taxon is dated at c. 65 Ma, nearly coincident with the end of the Cretaceous.Read the article »
Article DOI: 10.5252/g2015n4a1
Project DOI: 10.7934/P1070, http://dx.doi.org/10.7934/P1070
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 23911 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 426 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 1043 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:360/66 |
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MorphoBank Project 1070
MorphoBank Project 1070
- Creation Date:
13 November 2013 - Publication Date:
06 November 2017 - Project views: 19266
- Matrix downloads: 38
Authors' Institutions
- Muséum national d'Histoire naturelle, Paris (Natural History Museum, Paris)
- Centre National de la Recherche Scientifique (CNRS)
- Université Pierre et Marie Curie, UPMC, Paris VI (Pierre and Marie Curie University)
- Sorbonne Université
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Guillaume Billet Project Administrator | 59 | 0 | 0 | 426 | 0 | 0 | 16066 (14918, 0, 1148) | 0 | 0 | 0 | ||||
Maureen Admin Full membership | 0 | 0 | 0 | 0 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 | ||||
MorphoBank Curator Full membership | 0 | 1 | 0 | 0 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 | ||||
Christian Muizon Full membership | 13 | 0 | 1 | 0 | 0 | 0 | 7845 (7247, 0, 598) | 0 | 0 | 3 |
Taxonomic Overview for Matrix 'M2350' (72 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Vincelestes Last Modified in 11/06/17 | 12 | 386 | 385 | 0 | 29 | 0 | 0 | 4 |
[2] † Deltatheridium Last Modified in 11/06/17 | 151 | 266 | 265 | 0 | 10 | 0 | 0 | 4 |
[3] † Mayulestes Last Modified in 11/06/17 | 41 | 368 | 368 | 0 | 17 | 0 | 0 | 4 |
[4] † Pucadelphys Last Modified in 11/06/17 | 9 | 406 | 403 | 0 | 14 | 0 | 0 | 4 |
[5] † Eomaia Last Modified in 11/06/17 | 235 | 190 | 188 | 0 | 3 | 0 | 0 | 4 |
[6] † Prokennalestes Last Modified in 11/06/17 | 231 | 197 | 192 | 0 | 3 | 0 | 0 | 4 |
[7] † Zhelestes Last Modified in 11/06/17 | 260 | 170 | 164 | 0 | 2 | 0 | 0 | 4 |
[8] † Cimolestes Last Modified in 11/06/17 | 261 | 171 | 162 | 0 | 3 | 0 | 0 | 4 |
[9] † Maelestes Last Modified in 11/06/17 | 111 | 321 | 313 | 0 | 2 | 0 | 0 | 4 |
[10] † Kennalestes Last Modified in 11/06/17 | 104 | 315 | 311 | 0 | 11 | 0 | 0 | 4 |
[11] † Asioryctes Last Modified in 11/06/17 | 63 | 355 | 349 | 0 | 13 | 0 | 0 | 4 |
[12] † Kulbeckia Last Modified in 11/06/17 | 220 | 204 | 197 | 0 | 9 | 0 | 0 | 4 |
[13] † Zalambdalestes Last Modified in 11/06/17 | 38 | 391 | 377 | 0 | 11 | 0 | 0 | 4 |
[14] † Leptictis Last Modified in 11/06/17 | 12 | 407 | 406 | 0 | 8 | 0 | 0 | 4 |
[15] † Didelphodus Last Modified in 11/06/17 | 234 | 189 | 188 | 0 | 4 | 0 | 0 | 4 |
[16] † Alcidedorbignya Last Modified in 11/06/17 | 0 | 421 | 420 | 0 | 6 | 0 | 0 | 4 |
[17] † Pantolambda Last Modified in 11/06/17 | 26 | 395 | 394 | 0 | 6 | 0 | 0 | 4 |
[18] † Bemalambda Last Modified in 11/06/17 | 109 | 315 | 313 | 0 | 4 | 0 | 0 | 4 |
[19] † Harpyodus Last Modified in 11/06/17 | 340 | 86 | 86 | 0 | 0 | 0 | 0 | 4 |
[20] † Coryphodon Last Modified in 11/06/17 | 108 | 317 | 314 | 0 | 4 | 0 | 0 | 4 |
[21] † Azygonyx-Esthonyx Last Modified in 11/06/17 | 136 | 285 | 284 | 0 | 6 | 0 | 0 | 4 |
[22] † Trogosus Last Modified in 11/06/17 | 95 | 322 | 319 | 0 | 12 | 0 | 0 | 4 |
[23] † Protungulatum Last Modified in 11/06/17 | 211 | 219 | 211 | 0 | 4 | 0 | 0 | 4 |
[24] † Vulpavus Last Modified in 11/06/17 | 76 | 359 | 343 | 0 | 7 | 0 | 0 | 4 |
[25] † Miacis Last Modified in 11/06/17 | 95 | 333 | 325 | 0 | 6 | 0 | 0 | 4 |
[26] † Cynodictis Last Modified in 11/06/17 | 108 | 313 | 309 | 0 | 8 | 0 | 0 | 4 |
[27] † Diacodexis Last Modified in 11/06/17 | 83 | 339 | 335 | 0 | 8 | 0 | 0 | 4 |
[28] † Dichobune Last Modified in 11/06/17 | 129 | 292 | 291 | 0 | 6 | 0 | 0 | 4 |
[29] † Acotherulum Last Modified in 11/06/17 | 130 | 292 | 289 | 0 | 7 | 0 | 0 | 4 |
[30] † Hyopsodus Last Modified in 11/06/17 | 18 | 408 | 395 | 0 | 13 | 0 | 0 | 4 |
[31] † Meniscotherium Last Modified in 11/06/17 | 15 | 404 | 398 | 0 | 13 | 0 | 0 | 4 |
[32] † Phenacodus Last Modified in 11/06/17 | 35 | 386 | 377 | 0 | 14 | 0 | 0 | 4 |
[33] † Pleuraspidotherium Last Modified in 11/06/17 | 37 | 383 | 380 | 0 | 9 | 0 | 0 | 4 |
[34] † Maiorana Last Modified in 11/06/17 | 153 | 268 | 268 | 0 | 5 | 0 | 0 | 4 |
[35] † Baioconodon Last Modified in 11/06/17 | 160 | 263 | 262 | 0 | 4 | 0 | 0 | 4 |
[36] † Arctocyonides Last Modified in 11/06/17 | 99 | 321 | 319 | 0 | 8 | 0 | 0 | 4 |
[37] † Arctocyon Last Modified in 11/06/17 | 40 | 374 | 372 | 0 | 14 | 0 | 0 | 4 |
[38] Ptilocercus Last Modified in 12/05/13 | 4 | 412 | 408 | 0 | 14 | 0 | 0 | 4 |
[39] † Plesiadapis Last Modified in 11/06/17 | 33 | 390 | 373 | 0 | 20 | 0 | 0 | 4 |
[40] † Northarctus Last Modified in 11/06/17 | 39 | 376 | 369 | 0 | 18 | 0 | 0 | 4 |
[41] † Adapis-Magnadapis Last Modified in 11/06/17 | 54 | 364 | 354 | 0 | 18 | 0 | 0 | 4 |
[42] † Tribosphenomys Last Modified in 11/06/17 | 243 | 153 | 153 | 0 | 30 | 0 | 0 | 4 |
[43] † Paramys Last Modified in 11/06/17 | 32 | 354 | 349 | 0 | 45 | 0 | 0 | 4 |
[44] † Rhombomylus Last Modified in 11/06/17 | 22 | 368 | 360 | 0 | 44 | 0 | 0 | 4 |
[45] † Gomphos Last Modified in 11/06/17 | 101 | 288 | 286 | 0 | 39 | 0 | 0 | 4 |
[46] † Mimotona Last Modified in 11/06/17 | 266 | 130 | 126 | 0 | 34 | 0 | 0 | 4 |
[47] Blarina Last Modified in 12/05/13 | 21 | 382 | 373 | 0 | 32 | 0 | 0 | 4 |
[48] Erinaceus Last Modified in 12/05/13 | 2 | 414 | 402 | 0 | 22 | 0 | 0 | 4 |
[49] Solenodon Last Modified in 12/05/13 | 8 | 400 | 391 | 0 | 27 | 0 | 0 | 4 |
[50] † Eoryctes Last Modified in 11/06/17 | 204 | 215 | 210 | 0 | 12 | 0 | 0 | 4 |
[51] Potamogale Last Modified in 12/05/13 | 7 | 392 | 391 | 0 | 28 | 0 | 0 | 4 |
[52] Tenrec Last Modified in 12/05/13 | 8 | 396 | 389 | 0 | 29 | 0 | 0 | 4 |
[53] Orycteropus Last Modified in 12/05/13 | 10 | 293 | 287 | 0 | 129 | 0 | 0 | 4 |
[54] Rhynchocyon Last Modified in 12/05/13 | 18 | 380 | 378 | 0 | 30 | 0 | 0 | 4 |
[55] Procavia Last Modified in 12/05/13 | 1 | 404 | 395 | 0 | 30 | 0 | 0 | 4 |
[56] † Moeritherium Last Modified in 11/06/17 | 111 | 279 | 277 | 0 | 38 | 0 | 0 | 4 |
[57] Chaetophractus Last Modified in 12/05/13 | 2 | 287 | 287 | 0 | 137 | 0 | 0 | 4 |
[58] Dasypus Last Modified in 12/05/13 | 1 | 277 | 276 | 0 | 149 | 0 | 0 | 4 |
[59] Bradypus Last Modified in 12/05/13 | 4 | 277 | 273 | 0 | 149 | 0 | 0 | 4 |
[60] Tamandua Last Modified in 12/05/13 | 16 | 247 | 245 | 0 | 165 | 0 | 0 | 4 |
[61] † Colbertia Last Modified in 11/06/17 | 144 | 275 | 270 | 0 | 12 | 0 | 0 | 4 |
[62] † Plesiotypotherium Last Modified in 11/06/17 | 131 | 271 | 263 | 0 | 32 | 0 | 0 | 4 |
[63] † Protypotherium Last Modified in 11/06/17 | 106 | 315 | 306 | 0 | 14 | 0 | 0 | 4 |
[64] † Adinotherium Last Modified in 11/06/17 | 95 | 331 | 320 | 0 | 11 | 0 | 0 | 4 |
[65] † Notostylops Last Modified in 11/06/17 | 129 | 301 | 284 | 0 | 13 | 0 | 0 | 4 |
[66] † Pyrotherium Last Modified in 11/06/17 | 185 | 218 | 211 | 0 | 30 | 0 | 0 | 4 |
[67] † Trigonostylops Last Modified in 11/06/17 | 186 | 231 | 226 | 0 | 14 | 0 | 0 | 4 |
[68] † Astrapotherium Last Modified in 11/06/17 | 120 | 282 | 272 | 0 | 34 | 0 | 0 | 4 |
[69] † Miguelsoria Last Modified in 11/06/17 | 224 | 197 | 196 | 0 | 6 | 0 | 0 | 4 |
[70] † Proterotherium Last Modified in 11/06/17 | 55 | 362 | 353 | 0 | 18 | 0 | 0 | 4 |
[71] † Macrauchenia Last Modified in 11/06/17 | 119 | 301 | 296 | 0 | 11 | 0 | 0 | 4 |
[72] † Carodnia Last Modified in 11/06/17 | 247 | 172 | 170 | 0 | 9 | 0 | 0 | 4 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 19266 | |
Project overview | 1733 | |
Media views | 3287 | Media search (2816 views); M462204 (471 views); |
Matrix views | 1395 | Matrix landing page (1176 views); Pantod matrix (219 views); |
Taxon list | 9804 | |
Specimen list | 1296 | |
Views for media list | 1005 | |
Bibliography | 744 | |
Documents list | 2 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 232 | |
Matrix downloads | 38 | Pantod matrix (38 downloads); |
Project downloads | 194 |