Project 2436: R. M. D. Beck. 2017. The Skull of Epidolops ameghinoi from the Early Eocene Itaboraí Fauna, Southeastern Brazil, and the Affinities of the Extinct Marsupialiform Order Polydolopimorphia. Journal of Mammalian Evolution. 24 (4):373-414.
Abstract
The skull of the polydolopimorphian marsupialiform Epidolops ameghinoi is described in detail for the first time, based on a single well-preserved cranium and associated left and right dentaries plus additional craniodental fragments, all from the early Eocene (53–50 million year old) Itaboraí fauna in southeastern Brazil. Notable craniodental features of E. ameghinoi include absence of a masseteric process, very small maxillopalatine fenestrae, a prominent pterygoid fossa enclosed laterally by a prominent ectopterygoid crest, an absent or tiny transverse canal foramen, a simple, planar glenoid fossa, and a postglenoid foramen that is immediately posterior to the postglenoid process. Most strikingly, the floor of the hypotympanic sinus was apparently unossified, a feature found in several stem marsupials but absent in all known crown marsupials. "Type II" marsupialiform petrosals previously described from Itaboraí plausibly belong to E. ameghinoi; in published phylogenetic analyses, these petrosals fell outside (crown-clade) Marsupialia. "IMG VII" tarsals previously referred to E. ameghinoi do not share obvious synapomorphies with any crown marsupial clade, nor do they resemble those of the only other putative polydolopimorphians represented by tarsal remains, namely the argyrolagids. Most studies have placed Polydolopimorphia within Marsupialia, related to either Paucituberculata, or to Microbiotheria and Diprotodontia. However, diprotodonty almost certainly evolved independently in polydolopimorphians, paucituberculatans and diprotodontians, and Epidolops does not share obvious synapomorphies with any marsupial order. Epidolops is dentally specialized, but several morphological features appear to be more plesiomorphic than any crown marsupial. It seems likely Epidolops that falls outside Marsupialia, as do morphologically similar forms such as Bonapartherium and polydolopids. Argyrolagids differ markedly in their known morphology from Epidolops but share some potential apomorphies with paucituberculatans. It is proposed that Polydolopimorphia as currently recognised is polyphyletic, and that argyrolagids (and possibly other taxa currently included in Argyrolagoidea, such as groeberiids and patagoniids) are members of Paucituberculata. This hypothesis is supported by Bayesian non-clock phylogenetic analyses of a total evidence matrix comprising DNA sequence data from five nuclear protein-coding genes, indels, retroposon insertions, and morphological characters: Epidolops falls outside Marsupialia, whereas argyrolagids form a clade with the paucituberculatans Caenolestes and Palaeothentes, regardless of whether the Type II petrosals and IMG VII tarsals are used to score characters for Epidolops or not. There is no clear evidence for the presence of crown marsupials at Itaboraí, and it is possible that the origin and early evolution of Marsupialia was restricted to the "Austral Kingdom" (southern South America, Antarctica, and Australia).Read the article »
Article DOI: 10.1007/s10914-016-9357-6
Project DOI: 10.7934/P2436, http://dx.doi.org/10.7934/P2436
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 17055 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 546 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 636 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:444/102 |
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MorphoBank Project 2436
MorphoBank Project 2436
- Creation Date:
03 June 2016 - Publication Date:
01 December 2016 - Project views: 23652
- Media downloads: 2
- Matrix downloads: 33
Authors' Institutions
- University of New South Wales
- University of Salford
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Robin Beck Project Administrator | 42 | 1 | 1 | 546 | 0 | 0 | 17055 (16634, 0, 421) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M24202' (41 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] Ornithorhynchus Last Modified in 09/15/16 | 29 | 217 | 215 | 0 | 29 | 0 | 0 | 1 |
[2] Tachyglossus Last Modified in 09/15/16 | 24 | 222 | 220 | 0 | 29 | 0 | 0 | 1 |
[3] Vincelestes Last Modified in 09/15/16 | 79 | 185 | 184 | 0 | 10 | 0 | 0 | 1 |
[4] Ukhaatherium Last Modified in 09/15/16 | 165 | 107 | 107 | 0 | 1 | 0 | 0 | 1 |
[5] Asioryctes Last Modified in 09/15/16 | 152 | 119 | 119 | 0 | 2 | 0 | 0 | 1 |
[6] Deltatheridium Last Modified in 09/15/16 | 176 | 92 | 92 | 0 | 5 | 0 | 0 | 1 |
[7] Mayulestes Last Modified in 09/15/16 | 83 | 188 | 188 | 0 | 2 | 0 | 0 | 1 |
[8] Pucadelphys Last Modified in 09/15/16 | 55 | 220 | 216 | 0 | 2 | 0 | 0 | 1 |
[9] Andinodelphys Last Modified in 09/15/16 | 73 | 200 | 199 | 0 | 1 | 0 | 0 | 1 |
[10] Didelphis Last Modified in 09/15/16 | 2 | 279 | 268 | 0 | 3 | 0 | 0 | 1 |
[11] Monodelphis Last Modified in 09/15/16 | 3 | 275 | 267 | 0 | 3 | 0 | 0 | 1 |
[12] Caluromys Last Modified in 09/15/16 | 85 | 186 | 184 | 0 | 4 | 0 | 0 | 1 |
[13] Glironia Last Modified in 09/15/16 | 89 | 184 | 182 | 0 | 2 | 0 | 0 | 1 |
[14] Caenolestes Last Modified in 09/15/16 | 11 | 264 | 259 | 0 | 3 | 0 | 0 | 1 |
[15] Dasyuroides Last Modified in 09/15/16 | 12 | 262 | 256 | 0 | 5 | 0 | 0 | 1 |
[16] Dasyurus Last Modified in 09/15/16 | 8 | 276 | 263 | 0 | 2 | 0 | 0 | 1 |
[17] Phascogale Last Modified in 09/15/16 | 15 | 259 | 256 | 0 | 2 | 0 | 0 | 1 |
[18] Notoryctes Last Modified in 09/15/16 | 44 | 223 | 219 | 0 | 10 | 0 | 0 | 1 |
[19] Echymipera Last Modified in 09/15/16 | 9 | 263 | 260 | 0 | 4 | 0 | 0 | 1 |
[20] Perameles Last Modified in 09/15/16 | 4 | 270 | 265 | 0 | 4 | 0 | 0 | 1 |
[21] Dromiciops Last Modified in 09/15/16 | 7 | 265 | 263 | 0 | 3 | 0 | 0 | 1 |
[22] Trichosurus Last Modified in 09/15/16 | 4 | 273 | 265 | 0 | 4 | 0 | 0 | 1 |
[23] Phalanger Last Modified in 09/15/16 | 9 | 267 | 259 | 0 | 5 | 0 | 0 | 1 |
[24] Petaurus Last Modified in 09/15/16 | 2 | 269 | 265 | 0 | 6 | 0 | 0 | 1 |
[25] Pseudochirops Last Modified in 09/15/16 | 6 | 265 | 262 | 0 | 5 | 0 | 0 | 1 |
[26] Cercartetus Last Modified in 09/15/16 | 24 | 246 | 245 | 0 | 4 | 0 | 0 | 1 |
[27] Macropus Last Modified in 09/15/16 | 3 | 270 | 265 | 0 | 5 | 0 | 0 | 1 |
[28] Dendrolagus Last Modified in 09/15/16 | 11 | 259 | 256 | 0 | 6 | 0 | 0 | 1 |
[29] Dorcopsis Last Modified in 09/15/16 | 16 | 253 | 252 | 0 | 5 | 0 | 0 | 1 |
[30] Thylogale Last Modified in 09/15/16 | 20 | 249 | 248 | 0 | 5 | 0 | 0 | 1 |
[31] Vombatus Last Modified in 09/15/16 | 9 | 260 | 254 | 0 | 10 | 0 | 0 | 1 |
[32] Phascolarctos Last Modified in 09/15/16 | 10 | 255 | 255 | 0 | 8 | 0 | 0 | 1 |
[33] Asiatherium Last Modified in 09/15/16 | 216 | 58 | 57 | 0 | 0 | 0 | 0 | 1 |
[34] Herpetotherium Last Modified in 09/15/16 | 106 | 166 | 166 | 0 | 1 | 0 | 0 | 1 |
[35] Peradectidae Last Modified in 09/15/16 | 175 | 98 | 98 | 0 | 0 | 0 | 0 | 1 |
[36] Djarthia Last Modified in 09/15/16 | 179 | 96 | 91 | 0 | 3 | 0 | 0 | 1 |
[37] Palaeothentes Last Modified in 09/15/16 | 145 | 128 | 126 | 0 | 2 | 0 | 0 | 1 |
[38] Yalkaparidon Last Modified in 09/15/16 | 146 | 126 | 118 | 0 | 9 | 0 | 0 | 1 |
[39] Epidolops Last Modified in 09/15/16 | 178 | 94 | 94 | 0 | 1 | 0 | 0 | 1 |
[40] Argyrolagus Last Modified in 09/15/16 | 167 | 102 | 100 | 0 | 6 | 0 | 0 | 1 |
[41] Proargyrolagus Last Modified in 09/15/16 | 230 | 47 | 43 | 0 | 0 | 0 | 0 | 1 |
Taxonomic Overview for Matrix 'M24203' (41 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] Ornithorhynchus Last Modified in 09/15/16 | 29 | 217 | 215 | 0 | 29 | 0 | 0 | 1 |
[2] Tachyglossus Last Modified in 09/15/16 | 24 | 222 | 220 | 0 | 29 | 0 | 0 | 1 |
[3] Vincelestes Last Modified in 09/15/16 | 79 | 185 | 184 | 0 | 10 | 0 | 0 | 1 |
[4] Ukhaatherium Last Modified in 09/15/16 | 165 | 107 | 107 | 0 | 1 | 0 | 0 | 1 |
[5] Asioryctes Last Modified in 09/15/16 | 152 | 119 | 119 | 0 | 2 | 0 | 0 | 1 |
[6] Deltatheridium Last Modified in 09/15/16 | 176 | 92 | 92 | 0 | 5 | 0 | 0 | 1 |
[7] Mayulestes Last Modified in 09/15/16 | 83 | 188 | 188 | 0 | 2 | 0 | 0 | 1 |
[8] Pucadelphys Last Modified in 09/15/16 | 55 | 220 | 216 | 0 | 2 | 0 | 0 | 1 |
[9] Andinodelphys Last Modified in 09/15/16 | 73 | 200 | 199 | 0 | 1 | 0 | 0 | 1 |
[10] Didelphis Last Modified in 09/15/16 | 2 | 279 | 268 | 0 | 3 | 0 | 0 | 1 |
[11] Monodelphis Last Modified in 09/15/16 | 3 | 275 | 267 | 0 | 3 | 0 | 0 | 1 |
[12] Caluromys Last Modified in 09/15/16 | 85 | 186 | 184 | 0 | 4 | 0 | 0 | 1 |
[13] Glironia Last Modified in 09/15/16 | 89 | 184 | 182 | 0 | 2 | 0 | 0 | 1 |
[14] Caenolestes Last Modified in 09/15/16 | 11 | 264 | 259 | 0 | 3 | 0 | 0 | 1 |
[15] Dasyuroides Last Modified in 09/15/16 | 12 | 262 | 256 | 0 | 5 | 0 | 0 | 1 |
[16] Dasyurus Last Modified in 09/15/16 | 8 | 276 | 263 | 0 | 2 | 0 | 0 | 1 |
[17] Phascogale Last Modified in 09/15/16 | 15 | 259 | 256 | 0 | 2 | 0 | 0 | 1 |
[18] Notoryctes Last Modified in 09/15/16 | 44 | 223 | 219 | 0 | 10 | 0 | 0 | 1 |
[19] Echymipera Last Modified in 09/15/16 | 9 | 263 | 260 | 0 | 4 | 0 | 0 | 1 |
[20] Perameles Last Modified in 09/15/16 | 4 | 270 | 265 | 0 | 4 | 0 | 0 | 1 |
[21] Dromiciops Last Modified in 09/15/16 | 7 | 265 | 263 | 0 | 3 | 0 | 0 | 1 |
[22] Trichosurus Last Modified in 09/15/16 | 4 | 273 | 265 | 0 | 4 | 0 | 0 | 1 |
[23] Phalanger Last Modified in 09/15/16 | 9 | 267 | 259 | 0 | 5 | 0 | 0 | 1 |
[24] Petaurus Last Modified in 09/15/16 | 2 | 269 | 265 | 0 | 6 | 0 | 0 | 1 |
[25] Pseudochirops Last Modified in 09/15/16 | 6 | 265 | 262 | 0 | 5 | 0 | 0 | 1 |
[26] Cercartetus Last Modified in 09/15/16 | 24 | 246 | 245 | 0 | 4 | 0 | 0 | 1 |
[27] Macropus Last Modified in 09/15/16 | 3 | 270 | 265 | 0 | 5 | 0 | 0 | 1 |
[28] Dendrolagus Last Modified in 09/15/16 | 11 | 259 | 256 | 0 | 6 | 0 | 0 | 1 |
[29] Dorcopsis Last Modified in 09/15/16 | 16 | 253 | 252 | 0 | 5 | 0 | 0 | 1 |
[30] Thylogale Last Modified in 09/15/16 | 20 | 249 | 248 | 0 | 5 | 0 | 0 | 1 |
[31] Vombatus Last Modified in 09/15/16 | 9 | 260 | 254 | 0 | 10 | 0 | 0 | 1 |
[32] Phascolarctos Last Modified in 09/15/16 | 10 | 255 | 255 | 0 | 8 | 0 | 0 | 1 |
[33] Asiatherium Last Modified in 09/15/16 | 216 | 58 | 57 | 0 | 0 | 0 | 0 | 1 |
[34] Herpetotherium Last Modified in 09/15/16 | 106 | 166 | 166 | 0 | 1 | 0 | 0 | 1 |
[35] Peradectidae Last Modified in 09/15/16 | 175 | 98 | 98 | 0 | 0 | 0 | 0 | 1 |
[36] Djarthia Last Modified in 09/15/16 | 179 | 96 | 91 | 0 | 3 | 0 | 0 | 1 |
[37] Palaeothentes Last Modified in 09/15/16 | 145 | 128 | 126 | 0 | 2 | 0 | 0 | 1 |
[38] Yalkaparidon Last Modified in 09/15/16 | 146 | 126 | 118 | 0 | 9 | 0 | 0 | 1 |
[39] Epidolops Last Modified in 09/15/16 | 219 | 54 | 54 | 0 | 0 | 0 | 0 | 1 |
[40] Argyrolagus Last Modified in 09/15/16 | 167 | 102 | 100 | 0 | 6 | 0 | 0 | 1 |
[41] Proargyrolagus Last Modified in 09/15/16 | 230 | 47 | 43 | 0 | 0 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 23652 | |
Project overview | 2491 | |
Media views | 4314 | Media search (3752 views); M434666 (562 views); |
Matrix views | 2060 | Matrix landing page (1636 views); Morphological matrix B (220 views); Morphological matrix A (204 views); |
Documents list | 1332 | |
Taxon list | 9118 | |
Specimen list | 2224 | |
Views for media list | 1217 | |
Bibliography | 896 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 264 | |
Project downloads | 226 | |
Matrix downloads | 33 | Morphological matrix B (23 downloads); Morphological matrix A (10 downloads); |
Media downloads | 2 | M434666 (2 downloads); |
Document downloads | 3 | Total evidence matrix A (1 download); Total evidence matrix B (2 downloads); |