Project 4844: M. Buchwitz, C. Foth, I. Kogan, S. Voigt. 2012. On the use of osteoderm features in a phylogenetic approach on the internal relationships of the Chroniosuchia (Tetrapoda: Reptiliomorpha). Palaeontology. 55 (3):623-640.
Abstract
Chroniosuchians are an enigmatic Permian to Triassic group of crocodile-like basal tetrapods. Their conspicuous dorsal osteoderm systems include most of the group’s yet documented postcranial morphological variability but have hardly been considered in cladistic approaches. Aiming at the clarification of the internal relationships of the Chroniosuchia, we have carried out a parsimony analysis including, among others, 23 morphological and osteohistological osteoderm characters and 12 chroniosuchian taxa. According to the most parsimonious trees, taxa usually referred to Chroniosuchidae form a paraphyletic succession with Madygenerpeton pustulatus and Chroniosaurus dongusensis as the basalmost chroniosuchians and Uralerpeton tverdochlebovae as the sister group of Bystrowianidae (hypothesis A). However, the concurrent hypothesis of a basal split into monophyletic subtaxa Chroniosuchidae and Bystrowianidae (hypothesis B) is only slightly less parsimonious and supported by an alternative analysis which includes embolomeres as the only reptiliomorph outgroup. Searching for the better hypothesis, we compare the respective order of branching to the order of first occurrences in the fossil record, demonstrating that hypothesis A provides a better stratigraphic fit than hypothesis B. Accordingly, the last common ancestor of the yet known chroniosuchians had a series of broad complexly interlocking ‘chroniosuchid’ osteoderms that served as a protection carapace apart from supporting the trunk during terrestrial locomotion. The later evolution of chroniosuchian carapaces was marked by a stepwise increase in flexibility and size reduction, which resulted in a loss of protective function and in a reduction in trunk support function. The flexibility increase is paralleled by the evolution of the Crocodylomorpha whose extant members do not possess as extensively interlocking osteoderm systems as some of their Mesozoic relatives.Read the article »
Article DOI: 10.1111/j.1475-4983.2012.01137.x
Project DOI: 10.7934/P4844, http://dx.doi.org/10.7934/P4844
This project contains | Matrices |
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Download Project SDD File | Total scored cells: 0 Total media associated with cells: 0 Total labels associated with cell media: 0 |
Characters | |
Total characters: 73 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 154 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:73/0 |
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MorphoBank Project 4844
MorphoBank Project 4844
- Creation Date:
20 August 2023 - Publication Date:
21 August 2023 - Project views: 2055
Authors' Institutions
- Technische Universität Bergakademie Freiberg (Freiberg University of Mining and Technology)
- Bayerische Staatssammlung fuer Palaeontologie und Geologie
Members
member name | taxa | specimens | media | chars | character
| cell scorings (scored, NPA, "-") | cell
| rules | ||||||
Joyce Song Project Administrator | 30 | 1 | 1 | 73 | 0 | 0 | 0 (0, 0, 0) | 0 | 0 | 0 |
Taxonomic Overview for Matrix 'M29454' (30 Taxa)
taxon | unscored cells |
scored cells |
no cell support |
NPA cells |
"-" cells | cell images | labels on cell images |
member access |
[1] † Ichthyostega Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[2] † Pederpes Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[3] † Crassigyrinus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[4] † Eucritta Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[5] † Greererpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[6] † Balanerpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[7] † Cochleosaurus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[8] † Silvanerpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[9] † Anthracosaurus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[10] † Proterogyrinus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[11] † Eoherpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[12] † Palaeoherpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[13] † Pholiderpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[14] † Archeria Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[15] † Gephyrostegus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[16] † Seymouria Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[17] † Limnoscelis Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[18] † Asaphestera Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[19] † Chroniosuchus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[20] † Chroniosaurus dongusensis Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[21] † Chroniosaurus levis Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[22] † Uralerpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[23] † Jarilinus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[24] † Suchonica Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[25] † Madygenerpeton Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[26] † Bystrowiana Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[27] † Axitectum Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[28] † Dromotectum Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[29] † Synesuchus Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
[30] † Bystrowiella Last Modified in 08/20/23 | 73 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Project views
type | number of views | Individual items viewed (where applicable) |
Total project views | 2055 | |
Media views | 440 | Media search (356 views); M892511 (84 views); |
Matrix views | 115 | Matrix landing page (109 views); Matrix from PBDB (6 views); |
Documents list | 113 | |
Project overview | 173 | |
Bibliography | 72 | |
Views for media list | 130 | |
Specimen list | 228 | |
Taxon list | 784 |