Morphobank

Project 5251: R. R. Reisz, T. Maho, S. P. Modesto. 2024. Recumbirostran 'microsaurs' are not amniotes. Journal of Systematic Palaeontology. 22 (1):1-16.

Specimen: † Seymouria baylorensis (unvouchered)
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Abstract

Amniota is a tetrapod clade that includes extant mammals and reptiles, including birds, as well as a wealth of extinct taxa extending over 318 million years of Earth’s history. For over three decades, Amniota has been treated as a crown group, but the content of stem amniotes has varied among large-scale analyses of Palaeozoic tetrapods. Nine recent phylogenetic studies on Palaeozoic tetrapods, all derived from each other, have potentially changed our perspectives on amniote origins and early evolution. The first of these analyses posited that two particular clades of Palaeozoic tetrapods, Recumbirostra and Lysorophia, both previously considered to be lepospondyl stem-amniotes, are actually amniotes. This raises the possibility that early amniotes included both small fossorial and terrestrial animals, some of which show strong evidence of limb reduction. Here we show that the strange position of these small, often fossorial and limb-reduced tetrapods in Amniota is the result of two fundamental flaws: (1) the phylogenetic analysis combines two separate data matrices that were each designed to test only patterns of relationships among early anamniote tetrapods; and (2) the absence of key amniote characters. Our reanalysis of Palaeozoic tetrapod interrelationships reinstates recumbirostrans and lysorophians outside Amniota. The results of our study impact other recent studies that have simply accepted the codings in the data matrix that resulted in the hypothesis that recumbirostrans are amniotes and raises important questions about the initial diversification of amniotes and the evolution of fossoriality and limb reduction among tetrapods.

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Article DOI: 10.1080/14772019.2023.2296078

Project DOI: 10.7934/P5251, http://dx.doi.org/10.7934/P5251

This project contains	Matrices
4 Media 2 Matrices 2 Documents 69 Taxa 4 Specimens 390 Characters Total size of project's media files: 19.91M Download Project SDD File	Total scored cells: 35999 Total media associated with cells: 0 Total labels associated with cell media: 0
	Characters
	Total characters: 780 Total characters with associated media: 0 Total characters with media with labels: 0 Total character states: 922 Total character states with associated media: 0 Total character states with media with labels:0 Total unordered/ordered characters:780/0

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MorphoBank Project 5251

Creation Date:
17 May 2024
Publication Date:
21 May 2024

Authors' Institutions

Jilin University

University of Toronto

Cape Breton University

Members

MorphoBank Curator
Project Administrator

780

35999
(33578, 0, 2421)

Taxonomic Overview for Matrix 'M29826' (69 Taxa)

taxon	unscored cells	scored cells	no cell support	NPA cells	"-" cells	cell images	labels on cell images	member access
[1] † Eusthenopteron foordi Taxon name last Modified on 05/21/24	160	210	210	0	20	0	0	1
[2] † Panderichthys rhombolepis Taxon name last Modified on 05/21/24	275	115	115	0	0	0	0	1
[3] † Tiktaalik rosaea Taxon name last Modified on 05/21/24	102	254	253	0	35	0	0	1
[4] † Ventastega curonica Taxon name last Modified on 05/21/24	139	247	247	0	4	0	0	1
[5] † Acanthostega gunnari Taxon name last Modified on 05/21/24	21	364	363	0	6	0	0	1
[6] † Ichthyostega spp. Taxon name last Modified on 05/21/24	63	321	319	0	8	0	0	1
[7] † Crassigyrinus scoticus Taxon name last Modified on 05/21/24	90	293	293	0	7	0	0	1
[8] † Pederpes finneyae Taxon name last Modified on 05/21/24	175	211	211	0	4	0	0	1
[9] † Whatcheeria deltae Taxon name last Modified on 05/21/24	94	290	289	0	7	0	0	1
[10] † Ymeria denticulata Taxon name last Modified on 05/21/24	283	106	105	0	2	0	0	1
[11] † Lethiscus stocki Taxon name last Modified on 05/21/24	72	288	287	0	31	0	0	1
[12] † Coloraderpeton brilli Taxon name last Modified on 05/21/24	87	269	267	0	36	0	0	1
[13] † Eucritta melanolimnetes Taxon name last Modified on 05/21/24	181	202	202	0	7	0	0	1
[14] † Archeria crassidisca Taxon name last Modified on 05/21/24	53	326	325	0	12	0	0	1
[15] † Proterogyrinus scheelei Taxon name last Modified on 05/21/24	53	330	326	0	11	0	0	1
[16] † Baphetes spp. Taxon name last Modified on 05/21/24	150	232	232	0	8	0	0	1
[17] † Greererpeton burkemorani Taxon name last Modified on 05/21/24	21	352	351	0	18	0	0	1
[18] † Balanerpeton woodi Taxon name last Modified on 05/21/24	91	292	292	0	7	0	0	1
[19] † Dendrerpeton acadianum Taxon name last Modified on 05/21/24	50	334	332	0	8	0	0	1
[20] † Brachydectes newberryi Taxon name last Modified on 05/21/24	22	339	338	0	30	0	0	1
[21] † Edops craigi Taxon name last Modified on 05/21/24	106	269	269	0	15	0	0	1
[22] † Eryops megalocephalus Taxon name last Modified on 05/21/24	68	311	310	0	12	0	0	1
[23] † Micromelerpetontidae Taxon name last Modified on 05/21/24	219	165	164	0	7	0	0	1
[24] † Ecolsonia cutlerensis Taxon name last Modified on 05/21/24	211	176	174	0	5	0	0	1
[25] † Acheloma spp. Taxon name last Modified on 05/21/24	83	296	296	0	11	0	0	1
[26] † Tambachia trogallas Taxon name last Modified on 05/21/24	182	202	201	0	7	0	0	1
[27] † Branchiosauridae Taxon name last Modified on 05/21/24	221	163	161	0	8	0	0	1
[28] † Micropholis stowi Taxon name last Modified on 05/21/24	99	291	282	0	9	0	0	1
[29] † Platyrhinops lyelli Taxon name last Modified on 05/21/24	108	274	273	0	9	0	0	1
[30] † Eoscopus lockardi Taxon name last Modified on 05/21/24	96	291	286	0	8	0	0	1
[31] † Amphibamus grandiceps Taxon name last Modified on 05/21/24	210	178	178	0	2	0	0	1
[32] † Tersomius texensis Taxon name last Modified on 05/21/24	163	227	221	0	6	0	0	1
[33] † Doleserpeton annectens Taxon name last Modified on 05/21/24	72	305	303	0	15	0	0	1
[34] † Gerobatrachus hottoni Taxon name last Modified on 05/21/24	192	192	192	0	6	0	0	1
[35] † Eocaecilia micropodia Taxon name last Modified on 05/21/24	62	272	271	0	57	0	0	1
[36] Caudata Taxon name last Modified on 05/17/24	108	258	234	0	48	0	0	1
[37] † Triadobatrachus massinoti Taxon name last Modified on 05/21/24	239	124	120	0	31	0	0	1
[38] Anura Taxon name last Modified on 05/17/24	126	222	212	0	52	0	0	1
[39] † Albanerpetontidae Taxon name last Modified on 05/21/24	218	147	146	0	26	0	0	1
[40] † Pantylus cordatus Taxon name last Modified on 05/21/24	20	351	350	0	20	0	0	1
[41] † Quasicaecilia texana Taxon name last Modified on 05/21/24	224	148	148	0	18	0	0	1
[42] † Pelodosotis elongatum Taxon name last Modified on 05/21/24	53	319	318	0	19	0	0	1
[43] † Huskerpeton englehorni Taxon name last Modified on 05/21/24	121	249	249	0	20	0	0	1
[44] † Carrolla craddocki Taxon name last Modified on 05/21/24	130	220	220	0	40	0	0	1
[45] † Micraroter erythrogeios Taxon name last Modified on 05/21/24	102	270	268	0	20	0	0	1
[46] † Nannaroter mckinzei Taxon name last Modified on 05/21/24	173	198	198	0	19	0	0	1
[47] † Cardiocephalus peabodyi Taxon name last Modified on 05/21/24	210	173	172	0	8	0	0	1
[48] † Cardiocephalus sternbergi Taxon name last Modified on 05/21/24	204	172	171	0	15	0	0	1
[49] † Llistrofus pricei Taxon name last Modified on 05/21/24	132	239	239	0	19	0	0	1
[50] † Aletrimyti gaskillae Taxon name last Modified on 05/21/24	96	265	265	0	29	0	0	1
[51] † Dvellecanus carrolli Taxon name last Modified on 05/21/24	119	245	245	0	26	0	0	1
[52] † Rhynchonkos stovalli Taxon name last Modified on 05/21/24	109	255	255	0	26	0	0	1
[53] † Seymouria baylorensis Taxon name last Modified on 05/21/24	19	357	357	0	14	0	0	1
[54] † Limnoscelis paludis Taxon name last Modified on 05/21/24	23	347	347	0	20	0	0	1
[55] † Captorhinus laticeps Taxon name last Modified on 05/21/24	21	341	341	0	28	0	0	1
[56] † Opisthodontosaurus carrolli Taxon name last Modified on 05/21/24	180	198	198	0	12	0	0	1
[57] † Petrolacosaurus kansensis Taxon name last Modified on 05/21/24	33	340	339	0	18	0	0	1
[58] † Ophiacodon uniformis Taxon name last Modified on 05/21/24	9	359	359	0	22	0	0	1
[59] † Dimetrodon spp. Taxon name last Modified on 05/21/24	11	357	357	0	22	0	0	1
[60] † Diabloroter bolti Taxon name last Modified on 05/21/24	233	129	129	0	28	0	0	1
[61] † Infernovenator steenae Taxon name last Modified on 05/21/24	233	144	144	0	13	0	0	1
[62] † Joermungandr bolti Taxon name last Modified on 05/21/24	241	133	133	0	16	0	0	1
[63] † Batropetes fritschi Taxon name last Modified on 05/21/24	88	261	261	0	41	0	0	1
[64] † Nagini mazonensis Taxon name last Modified on 05/21/24	217	138	138	0	35	0	0	1
[65] † Proxilodon bonneri Taxon name last Modified on 05/21/24	285	96	96	0	9	0	0	1
[66] † Odonterpeton triangulare Taxon name last Modified on 05/21/24	223	155	155	0	12	0	0	1
[67] † Euryodus primus Taxon name last Modified on 05/21/24	149	225	225	0	16	0	0	1
[68] † Euryodus dalyae (composite) Taxon name last Modified on 05/21/24	94	278	278	0	18	0	0	1
[69] † Pariotichus brachyops Taxon name last Modified on 05/21/24	316	66	66	0	8	0	0	1

Taxonomic Overview for Matrix 'M29827' (69 Taxa)

taxon	unscored cells	scored cells	no cell support	NPA cells	"-" cells	cell images	labels on cell images	member access
[1] † Eusthenopteron foordi Taxon name last Modified on 05/21/24	160	210	210	0	20	0	0	1
[2] † Panderichthys rhombolepis Taxon name last Modified on 05/21/24	275	115	115	0	0	0	0	1
[3] † Tiktaalik rosaea Taxon name last Modified on 05/21/24	102	254	253	0	35	0	0	1
[4] † Ventastega curonica Taxon name last Modified on 05/21/24	139	247	247	0	4	0	0	1
[5] † Acanthostega gunnari Taxon name last Modified on 05/21/24	21	364	363	0	6	0	0	1
[6] † Ichthyostega spp. Taxon name last Modified on 05/21/24	63	321	319	0	8	0	0	1
[7] † Crassigyrinus scoticus Taxon name last Modified on 05/21/24	90	293	293	0	7	0	0	1
[8] † Pederpes finneyae Taxon name last Modified on 05/21/24	175	211	211	0	4	0	0	1
[9] † Whatcheeria deltae Taxon name last Modified on 05/21/24	94	290	289	0	7	0	0	1
[10] † Ymeria denticulata Taxon name last Modified on 05/21/24	283	106	105	0	2	0	0	1
[11] † Lethiscus stocki Taxon name last Modified on 05/21/24	72	288	287	0	31	0	0	1
[12] † Coloraderpeton brilli Taxon name last Modified on 05/21/24	87	269	267	0	36	0	0	1
[13] † Eucritta melanolimnetes Taxon name last Modified on 05/21/24	181	202	202	0	7	0	0	1
[14] † Archeria crassidisca Taxon name last Modified on 05/21/24	53	326	324	0	12	0	0	1
[15] † Proterogyrinus scheelei Taxon name last Modified on 05/21/24	53	330	325	0	11	0	0	1
[16] † Baphetes spp. Taxon name last Modified on 05/21/24	150	232	232	0	8	0	0	1
[17] † Greererpeton burkemorani Taxon name last Modified on 05/21/24	21	352	351	0	18	0	0	1
[18] † Balanerpeton woodi Taxon name last Modified on 05/21/24	91	292	292	0	7	0	0	1
[19] † Dendrerpeton acadianum Taxon name last Modified on 05/21/24	50	334	332	0	8	0	0	1
[20] † Edops craigi Taxon name last Modified on 05/21/24	111	264	264	0	15	0	0	1
[21] † Eryops megalocephalus Taxon name last Modified on 05/21/24	56	323	322	0	12	0	0	1
[22] † Micromelerpetontidae Taxon name last Modified on 05/21/24	226	158	157	0	7	0	0	1
[23] † Ecolsonia cutlerensis Taxon name last Modified on 05/21/24	215	172	170	0	5	0	0	1
[24] † Acheloma spp. Taxon name last Modified on 05/21/24	69	310	310	0	11	0	0	1
[25] † Tambachia trogallas Taxon name last Modified on 05/21/24	184	200	199	0	7	0	0	1
[26] † Branchiosauridae Taxon name last Modified on 05/21/24	223	161	159	0	8	0	0	1
[27] † Micropholis stowi Taxon name last Modified on 05/21/24	99	291	282	0	9	0	0	1
[28] † Platyrhinops lyelli Taxon name last Modified on 05/21/24	114	268	267	0	9	0	0	1
[29] † Eoscopus lockardi Taxon name last Modified on 05/21/24	97	290	285	0	8	0	0	1
[30] † Amphibamus grandiceps Taxon name last Modified on 05/21/24	206	182	182	0	2	0	0	1
[31] † Tersomius texensis Taxon name last Modified on 05/21/24	168	222	216	0	6	0	0	1
[32] † Doleserpeton annectens Taxon name last Modified on 05/21/24	64	313	311	0	15	0	0	1
[33] † Gerobatrachus hottoni Taxon name last Modified on 05/21/24	193	191	191	0	6	0	0	1
[34] † Eocaecilia micropodia Taxon name last Modified on 05/21/24	64	270	269	0	57	0	0	1
[35] Caudata Taxon name last Modified on 05/17/24	105	261	237	0	48	0	0	1
[36] † Triadobatrachus massinoti Taxon name last Modified on 05/21/24	244	119	115	0	31	0	0	1
[37] Anura Taxon name last Modified on 05/17/24	120	228	218	0	52	0	0	1
[38] † Albanerpetontidae Taxon name last Modified on 05/21/24	228	137	136	0	26	0	0	1
[39] † Pantylus cordatus Taxon name last Modified on 05/21/24	14	356	355	0	21	0	0	1
[40] † Brachydectes newberryi Taxon name last Modified on 05/21/24	24	336	335	0	31	0	0	1
[41] † Quasicaecilia texana Taxon name last Modified on 05/21/24	224	148	148	0	18	0	0	1
[42] † Pelodosotis elongatum Taxon name last Modified on 05/21/24	56	314	313	0	21	0	0	1
[43] † Huskerpeton englehorni Taxon name last Modified on 05/21/24	125	245	245	0	20	0	0	1
[44] † Carrolla craddocki Taxon name last Modified on 05/21/24	131	219	219	0	40	0	0	1
[45] † Micraroter erythrogeios Taxon name last Modified on 05/21/24	91	281	279	0	20	0	0	1
[46] † Nannaroter mckinzei Taxon name last Modified on 05/21/24	169	201	201	0	20	0	0	1
[47] † Cardiocephalus peabodyi Taxon name last Modified on 05/21/24	193	189	188	0	9	0	0	1
[48] † Cardiocephalus sternbergi Taxon name last Modified on 05/21/24	204	172	171	0	15	0	0	1
[49] † Llistrofus pricei Taxon name last Modified on 05/21/24	129	242	241	0	20	0	0	1
[50] † Aletrimyti gaskillae Taxon name last Modified on 05/21/24	81	280	280	0	29	0	0	1
[51] † Dvellecanus carrolli Taxon name last Modified on 05/21/24	119	244	244	0	27	0	0	1
[52] † Rhynchonkos stovalli Taxon name last Modified on 05/21/24	99	264	264	0	27	0	0	1
[53] † Seymouria baylorensis Taxon name last Modified on 05/21/24	20	356	355	0	14	0	0	1
[54] † Limnoscelis paludis Taxon name last Modified on 05/21/24	23	347	345	0	20	0	0	1
[55] † Captorhinus laticeps Taxon name last Modified on 05/21/24	21	341	340	0	28	0	0	1
[56] † Opisthodontosaurus carrolli Taxon name last Modified on 05/21/24	178	200	199	0	12	0	0	1
[57] † Petrolacosaurus kansensis Taxon name last Modified on 05/21/24	33	340	338	0	18	0	0	1
[58] † Ophiacodon uniformis Taxon name last Modified on 05/21/24	9	359	358	0	22	0	0	1
[59] † Dimetrodon spp. Taxon name last Modified on 05/21/24	11	357	356	0	22	0	0	1
[60] † Diabloroter bolti Taxon name last Modified on 05/21/24	233	129	129	0	28	0	0	1
[61] † Infernovenator steenae Taxon name last Modified on 05/21/24	233	144	144	0	13	0	0	1
[62] † Joermungandr bolti Taxon name last Modified on 05/21/24	241	133	133	0	16	0	0	1
[63] † Batropetes fritschi Taxon name last Modified on 05/21/24	88	261	261	0	41	0	0	1
[64] † Nagini mazonensis Taxon name last Modified on 05/21/24	217	138	138	0	35	0	0	1
[65] † Proxilodon bonneri Taxon name last Modified on 05/21/24	285	96	96	0	9	0	0	1
[66] † Odonterpeton triangulare Taxon name last Modified on 05/21/24	223	155	155	0	12	0	0	1
[67] † Euryodus primus Taxon name last Modified on 05/21/24	149	225	225	0	16	0	0	1
[68] † Euryodus dalyae (composite) Taxon name last Modified on 05/21/24	94	278	278	0	18	0	0	1
[69] † Pariotichus brachyops Taxon name last Modified on 05/21/24	316	66	66	0	8	0	0	1