Project 2554: C. de Muizon, G.Bianucci, M. Martínez-Cáceres, O. Lambert. 2019. Mystacodon selenensis, the earliest known toothed mysticete (Cetacea, Mammalia) from the late Eocene of Peru: anatomy, phylogeny, and feeding adaptations. Geodiversitas. 41 (11):401-499.
Abstract
Mystacodon selenensis Lambert, Martínez-Cáceres, Bianucci, Di Celma, Salas-Gismondi, Steurbaut, Urbina & Muizon, 2017 is a toothed mysticete that represents the earliest member of the suborder in the current state of knowledge. Its holotype is a relatively complete skeleton from the upper Eocene (early Priabonian, c. 36.4 Ma) Yumaque Member of the Paracas Formation from the southern coast of Peru. The thorough description of this specimen is presented here and reveals numerous similarities with the contemporaneous basilosaurids including the retention of an innominate that originally articulated to the unpreserved hind limb. However, several characters of M. selenensis clearly relate this taxon to the mysticetes, such as the large palate with a dorsoventrally flattened rostrum, the posterior extension of the palate with an infraorbital plate of the maxilla, the shortening of the premaxillary part of the rostrum, the zygomatic process of the squamosal being closely apposed to the postorbital process of the frontal, and the humeral head being oriented more proximally than posteriorly. A parsimony analysis retrieves Mystacodon as the earliest diverging branch of the Mysticeti with no close phylogenetic relationship with Llanocetus the second oldest known mysticete (c. 34.2 Ma). The dental formula of M. selenensis is that of basilosaurids (I 3/3, C 1/1, P 4/4, M 2/3). The anterior teeth (incisors and canine) are distinctly proportionally smaller than in basilosaurids, whereas the cheek teeth are very close in relative length, but are relatively larger than in most other toothed mysticetes (except Coronodon). The large cheek teeth of Mystacodon suggest a raptorial feeding strategy, probably assisted with some degree of suction, as indicated by the large size of the palate. The anterior teeth of the holotype display a subhorizontal apical wear facet and the cheek teeth a moderately sloping wear surface, differing from the subvertical attrition facets of basilosaurids. This pattern suggests an efficient dental abrasion resulting from feeding upon abrasive food items or/and from the ingestion of sediment during prey capture, which could indicate some degree of bottom feeding. On the forelimb, the size and orientation of the acromion, the great length of the deltopectoral crest, the massiveness of the olecranon of the ulna, and the strong radial anterior process indicate powerful shoulder movements, which suggest an active use of the forelimb when foraging for food on the sea floor. The robustness of digits and the pachyosteosclerosis of ribs with pestle-like distal end corroborate such a scenario. Mystacodon selenensis represents a first step in the evolutionary history of feeding adaptations of early mysticetes; the latter are likely to have experimented an abundant set of feeding strategies and were probably very eclectic in prey choice and capture before hyperspecialized filter feeding became widespread in the suborder.Read the article »
Article DOI: 10.5252/geodiversitas2019v41a11
Project DOI: 10.7934/P2554, http://dx.doi.org/10.7934/P2554
This project contains | Matrices |
---|---|
Download Project SDD File | Total scored cells: 9035 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 282 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 680 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:257/25 |
Currently Viewing:
MorphoBank Project 2554
MorphoBank Project 2554
- Creation Date:
08 November 2016 - Publication Date:
31 May 2019 - Project views: 16789
- Matrix downloads: 14
Authors' Institutions
- Muséum national d'Histoire naturelle, Paris (Natural History Museum, Paris)
- Centre National de la Recherche Scientifique (CNRS)
- Royal Belgian Institute of Natural Sciences
- Sorbonne Université
- University of Pisa
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||||||||||
Christian Muizon Project Administrator | 46 | 1 | 1 | 282 | 0 | 178 | 0 | 0 | 9035 (8534, 0, 501) | 0 | 0 | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M25739' (43 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Zygorhiza kochii Last Modified in 08/16/19 | 19 | 256 | 256 | 0 | 7 | 0 | 0 | 1 |
[2] † Cynthiacetus peruvianus Last Modified in 11/29/18 | 19 | 259 | 258 | 0 | 5 | 0 | 0 | 1 |
[3] † Archaeodelphis patrius Last Modified in 11/29/18 | 160 | 117 | 117 | 0 | 5 | 0 | 0 | 1 |
[4] † Simocetus rayii Last Modified in 11/29/18 | 97 | 180 | 180 | 0 | 5 | 0 | 0 | 1 |
[5] † Waipatia maerewhenua Last Modified in 11/29/18 | 42 | 230 | 230 | 0 | 10 | 0 | 0 | 1 |
[6] Squalodon spp Last Modified in 11/29/18 | 38 | 233 | 232 | 0 | 12 | 0 | 0 | 1 |
[7] Tursiops truncatus Last Modified in 11/29/18 | 3 | 257 | 257 | 0 | 22 | 0 | 0 | 1 |
[8] Physeter macrocephalus Last Modified in 11/29/18 | 8 | 236 | 233 | 0 | 41 | 0 | 0 | 1 |
[9] † Mystacodon selenensis Last Modified in 11/29/18 | 133 | 146 | 146 | 0 | 3 | 0 | 0 | 1 |
[10] † Llanocetus denticrenatus Last Modified in 11/29/18 | 97 | 181 | 181 | 0 | 4 | 0 | 0 | 1 |
[11] † Coronodon havensteini Last Modified in 11/29/18 | 61 | 216 | 216 | 0 | 5 | 0 | 0 | 1 |
[12] † Janjucetus hunderi Last Modified in 11/29/18 | 91 | 186 | 186 | 0 | 5 | 0 | 0 | 1 |
[13] † Mammalodon colliveri Last Modified in 11/29/18 | 96 | 180 | 180 | 0 | 6 | 0 | 0 | 1 |
[14] † Fucaia goedertorum Last Modified in 08/16/19 | 79 | 201 | 200 | 0 | 3 | 0 | 0 | 1 |
[15] † Aetiocetus cotylalveus Last Modified in 11/29/18 | 111 | 170 | 170 | 0 | 1 | 0 | 0 | 1 |
[16] † Aetiocetus polydentatus Last Modified in 11/29/18 | 97 | 183 | 183 | 0 | 2 | 0 | 0 | 1 |
[17] † Aetiocetus weltoni Last Modified in 11/29/18 | 84 | 196 | 196 | 0 | 2 | 0 | 0 | 1 |
[18] † ChM pv4745 Last Modified in 08/16/19 | 142 | 137 | 137 | 0 | 3 | 0 | 0 | 1 |
[19] † ChM pv5720 Last Modified in 08/16/19 | 104 | 173 | 173 | 0 | 5 | 0 | 0 | 1 |
[20] † Micromysticetus rothauseni Last Modified in 11/29/18 | 189 | 90 | 90 | 0 | 3 | 0 | 0 | 1 |
[21] † Yamatocetus canaliculatus Last Modified in 11/29/18 | 71 | 199 | 199 | 0 | 12 | 0 | 0 | 1 |
[22] † Eomysticetus whitmorei Last Modified in 11/29/18 | 82 | 187 | 187 | 0 | 13 | 0 | 0 | 1 |
[23] † Morenocetus parvus Last Modified in 11/29/18 | 163 | 114 | 114 | 0 | 5 | 0 | 0 | 1 |
[24] Balaena mysticetus Last Modified in 11/29/18 | 6 | 256 | 254 | 0 | 22 | 0 | 0 | 1 |
[25] Eubalaena spp. Last Modified in 11/29/18 | 2 | 264 | 258 | 0 | 22 | 0 | 0 | 1 |
[26] Caperea marginata Last Modified in 11/29/18 | 5 | 259 | 253 | 0 | 24 | 0 | 0 | 1 |
[27] † Miocaperea pulchra Last Modified in 11/29/18 | 120 | 144 | 143 | 0 | 19 | 0 | 0 | 1 |
[28] † Cetotherium rathkii Last Modified in 11/29/18 | 120 | 145 | 145 | 0 | 17 | 0 | 0 | 1 |
[29] † Cetotherium riabinini Last Modified in 11/29/18 | 73 | 194 | 194 | 0 | 15 | 0 | 0 | 1 |
[30] † Piscobalaena nana Last Modified in 11/29/18 | 17 | 248 | 246 | 0 | 19 | 0 | 0 | 1 |
[31] † Herpetocetus morrowi Last Modified in 11/29/18 | 46 | 220 | 219 | 0 | 17 | 0 | 0 | 1 |
[32] † Herpetocetus transatlanticus Last Modified in 11/29/18 | 156 | 117 | 117 | 0 | 9 | 0 | 0 | 1 |
[33] † Herpetocetus bramblei Last Modified in 11/29/18 | 119 | 145 | 145 | 0 | 18 | 0 | 0 | 1 |
[34] † Diorocetus hiatus Last Modified in 11/29/18 | 52 | 218 | 218 | 0 | 12 | 0 | 0 | 1 |
[35] † Aglaocetus patulus Last Modified in 11/29/18 | 80 | 191 | 189 | 0 | 13 | 0 | 0 | 1 |
[36] † Aglaocetus moreni Last Modified in 11/29/18 | 124 | 146 | 146 | 0 | 12 | 0 | 0 | 1 |
[37] † Parietobalaena campiniana Last Modified in 11/29/18 | 113 | 156 | 156 | 0 | 13 | 0 | 0 | 1 |
[38] † Parietobalaena palmeri Last Modified in 11/29/18 | 53 | 222 | 217 | 0 | 12 | 0 | 0 | 1 |
[39] † Pelocetus calvertensis Last Modified in 11/29/18 | 45 | 224 | 224 | 0 | 13 | 0 | 0 | 1 |
[40] Eschrichtius robustus Last Modified in 11/29/18 | 4 | 266 | 261 | 0 | 17 | 0 | 0 | 1 |
[41] Megaptera novaeangliae Last Modified in 11/29/18 | 4 | 265 | 263 | 0 | 15 | 0 | 0 | 1 |
[42] Balaenoptera acutorostrata Last Modified in 11/29/18 | 3 | 263 | 262 | 0 | 17 | 0 | 0 | 1 |
[43] Balaenoptera physalus Last Modified in 11/29/18 | 4 | 264 | 262 | 0 | 16 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 16789 | |
Project overview | 1541 | |
Matrix views | 955 | Matrix landing page (821 views); Mystacodon (133 views); Coates et al. Matrix (1 view); |
Taxon list | 8146 | |
Media views | 2856 | Media search (2437 views); M462201 (419 views); |
Bibliography | 597 | |
Specimen list | 1780 | |
Views for media list | 899 | |
Documents list | 15 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 194 | |
Project downloads | 180 | |
Matrix downloads | 14 | Mystacodon (14 downloads); |