Project 2553: M. I. Coates, R. W. Gess, J. A. Finarelli, K. E. Criswell, K. Tietjen. 2017. A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes. Nature. 541 (7636):208-211.
Abstract
Chimaeroid fishes (Holocephali) are one of the four principal divisions of modern gnathostomes (jawed vertebrates). Despite only 47 described living species, chimaeroids are the focus of resurgent interest as potential archives of genomic data and for the unique perspective they provide on chondrichthyan and gnathostome ancestral conditions. Chimaeroids are also noteworthy for their highly derived body plan. However, like other living groups with distinctive anatomies, fossils have been of limited use in unraveling their evolutionary origin as the earliest recognized examples already exhibit many of the specializations present in Recent forms. Here we report the results of a Computed Tomography (CT) analysis of Dwykaselachus, an enigmatic chondrichthyan braincase from the ~280 million year old Karoo sediments of South Africa. Externally, the braincase is that of a symmoriid shark and is by far the most complete uncrushed example yet discovered. Internally the morphology exhibits otherwise characteristically chimaeroid specializations, including the otic labyrinth arrangement and the brain space configuration relative to exceptionally large orbits. These results have significant implications for our view of modern chondrichthyan origins, add robust structure to the phylogeny of early crown group gnathostomes, reveal preconditions that suggest an initial morpho-functional basis for the derived chimaeroid cranium, and shed new light on the chondrichthyan response to the end-Devonian extinction.Read the article »
Article DOI: 10.1038/nature20806
Project DOI: 10.7934/P2553, http://dx.doi.org/10.7934/P2553
This project contains | Matrices |
---|---|
Download Project SDD File | Total scored cells: 3472 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 145 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 301 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:145/0 |
Currently Viewing:
MorphoBank Project 2553
MorphoBank Project 2553
- Creation Date:
08 November 2016 - Publication Date:
14 January 2017 - Project views: 25555
- Matrix downloads: 12
This research
supported by
Authors' Institutions
- University College Dublin
- University of Chicago
- Rhodes University
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||||||||||
John Finarelli Project Administrator | 37 | 1 | 1 | 145 | 0 | 0 | 0 | 0 | 3472 (3099, 0, 373) | 0 | 0 | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M24326' (37 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Acanthodes Last Modified in 11/08/16 | 12 | 115 | 115 | 0 | 18 | 0 | 0 | 1 |
[2] † Akmonistion Last Modified in 11/08/16 | 29 | 108 | 108 | 0 | 8 | 0 | 0 | 1 |
[3] † Brochoadmones Last Modified in 11/08/16 | 89 | 48 | 48 | 0 | 8 | 0 | 0 | 1 |
[4] Chimaeroidei Last Modified in 01/14/17 | 1 | 128 | 128 | 0 | 16 | 0 | 0 | 1 |
[5] † Chondrenchelys Last Modified in 11/08/16 | 38 | 91 | 91 | 0 | 16 | 0 | 0 | 1 |
[6] † Cladodoides Last Modified in 11/08/16 | 60 | 78 | 78 | 0 | 7 | 0 | 0 | 1 |
[7] † Cladoselache Last Modified in 11/08/16 | 53 | 84 | 84 | 0 | 8 | 0 | 0 | 1 |
[8] † Cobelodus Last Modified in 11/08/16 | 46 | 88 | 88 | 0 | 11 | 0 | 0 | 1 |
[9] † Cowralepis Last Modified in 11/08/16 | 84 | 47 | 47 | 0 | 14 | 0 | 0 | 1 |
[10] † Debeerius Last Modified in 11/08/16 | 38 | 96 | 96 | 0 | 11 | 0 | 0 | 1 |
[11] † Dicksonosteus Last Modified in 11/08/16 | 34 | 100 | 100 | 0 | 11 | 0 | 0 | 1 |
[12] † Doliodus Last Modified in 11/08/16 | 64 | 72 | 72 | 0 | 9 | 0 | 0 | 1 |
[13] † Dwykaselachus Last Modified in 11/08/16 | 69 | 71 | 71 | 0 | 5 | 0 | 0 | 1 |
[14] † Egertonodus Last Modified in 11/08/16 | 1 | 134 | 134 | 0 | 10 | 0 | 0 | 1 |
[15] † Entelognathus Last Modified in 11/08/16 | 78 | 57 | 57 | 0 | 10 | 0 | 0 | 1 |
[16] † Gladbachus Last Modified in 11/08/16 | 66 | 67 | 67 | 0 | 12 | 0 | 0 | 1 |
[17] † Guiyu Last Modified in 11/08/16 | 67 | 68 | 68 | 0 | 10 | 0 | 0 | 1 |
[18] † Hamiltonichthys Last Modified in 11/08/16 | 45 | 90 | 90 | 0 | 10 | 0 | 0 | 1 |
[19] † Helodus Last Modified in 11/08/16 | 44 | 92 | 91 | 0 | 10 | 0 | 0 | 1 |
[20] † Iniopera Last Modified in 11/08/16 | 21 | 111 | 110 | 0 | 14 | 0 | 0 | 1 |
[21] † Janusiscus Last Modified in 11/08/16 | 89 | 48 | 48 | 0 | 8 | 0 | 0 | 1 |
[22] † Kathemacanthus Last Modified in 11/08/16 | 84 | 47 | 47 | 0 | 14 | 0 | 0 | 1 |
[23] † Kawichthys Last Modified in 11/08/16 | 86 | 55 | 55 | 0 | 4 | 0 | 0 | 1 |
[24] † Ligulalepis Last Modified in 11/08/16 | 77 | 62 | 62 | 0 | 6 | 0 | 0 | 1 |
[25] † Mimipiscis Last Modified in 11/08/16 | 2 | 131 | 131 | 0 | 12 | 0 | 0 | 1 |
[26] † Onychoselache Last Modified in 11/08/16 | 66 | 69 | 69 | 0 | 10 | 0 | 0 | 1 |
[27] † Orthacanthus Last Modified in 11/08/16 | 8 | 127 | 127 | 0 | 10 | 0 | 0 | 1 |
[28] † Ozarcus fm 13242 Last Modified in 11/08/16 | 38 | 100 | 100 | 0 | 7 | 0 | 0 | 1 |
[29] † Poracanthodes Last Modified in 11/08/16 | 96 | 42 | 42 | 0 | 7 | 0 | 0 | 1 |
[30] † Psarolepis Last Modified in 11/08/16 | 65 | 71 | 71 | 0 | 9 | 0 | 0 | 1 |
[31] † Ptomacanthus Last Modified in 11/08/16 | 82 | 55 | 55 | 0 | 8 | 0 | 0 | 1 |
[32] † Pucapampella Last Modified in 11/08/16 | 66 | 67 | 67 | 0 | 12 | 0 | 0 | 1 |
[33] † Ramirosuarezia Last Modified in 11/08/16 | 88 | 48 | 48 | 0 | 9 | 0 | 0 | 1 |
[34] Squalus Last Modified in 11/08/16 | 1 | 131 | 131 | 0 | 13 | 0 | 0 | 1 |
[35] † Synechodus Last Modified in 11/08/16 | 53 | 82 | 82 | 0 | 10 | 0 | 0 | 1 |
[36] † Tamiobatis Last Modified in 11/08/16 | 46 | 92 | 92 | 0 | 7 | 0 | 0 | 1 |
[37] † Tristychius Last Modified in 11/08/16 | 9 | 127 | 127 | 0 | 9 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 25555 | |
Project overview | 2417 | |
Media views | 4205 | Media search (3455 views); M435792 (750 views); |
Matrix views | 1765 | Matrix landing page (1479 views); Coates et al. Matrix (286 views); |
Taxon list | 12828 | |
Specimen list | 2070 | |
Views for media list | 1328 | |
Bibliography | 939 | |
Documents list | 3 |
Project downloads
type | number of downloads | Individual items downloaded (where applicable) |
Total downloads from project | 244 | |
Project downloads | 232 | |
Matrix downloads | 12 | Coates et al. Matrix (12 downloads); |