Tags

Type your tag names separated by a space and hit enter

The postcranial anatomy of Brasilodon quadrangularis and the acquisition of mammaliaform traits among non-mammaliaform cynodonts.
PLoS One. 2019; 14(5):e0216672.Plos

Abstract

Brasilodon quadrangularis (Cynodontia, Probainognathia) is an iconic non-mammaliaform cynodont from the Late Triassic of Brazil (Riograndia Assemblage Zone, Candelária Sequence), being considered as the sister taxon of Mammaliaformes. Although its phylogenetic position is very important, several aspects of its postcranial anatomy remain unclear or unstudied. Here, we present a detailed description of the postcranial elements referred to Brasilodon, including previously mentioned specimens and new ones, which add relevant information about its postcranial morphology and provide a new insight into the anatomical transition between advanced non-mammaliaform cynodonts and early mammaliaforms. Functional and ecological implications are also investigated, based on the postcranial morphology and muscular reconstructions. The postcranium of Brasilodon differs from most non-mammaliaform cynodonts and presents similarities with tritylodontids, early mammaliaforms and extant therians, such as a ventrally oriented scapular glenoid facet, a distinct and ossified greater humeral tubercle, lack of ectepicondylar foramen, olecranon process, hemispherical humeral and femoral heads and a prominent intertrochanteric crest. The humeral torsion, the length of the deltopectoral crest, the large bicipital groove and the well-developed lesser tubercle, indicate that the forelimb of Brasilodon was hold in a semi-sprawling position, with well-developed adductor muscles to maintain the body off the ground. The short femoral neck and the strong medial projection of the femoral head indicate the femur was held in a more erect posture than in basal non-mammaliaform cynodonts. The anterodorsally projected iliac blade with reduced postacetabular process, reduction of the anterior part of the pubis, medially located lesser trochanter indicate a basically mammalian pattern of pelvic musculature, able to swing the femur in a nearly parasagittal plane.

Authors+Show Affiliations

Programa de Pós-Graduação em Geociências, Universidade Federal do Rio Grande do Sul, Agronomia, Porto Alegre, Rio Grande do Sul, Brazil.CONICET-Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Buenos Aires, Argentina. Departamento de Paleontologia e Estratigrafia, Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Agronomia, Porto Alegre, Rio Grande do Sul, Brazil.Programa de Pós-Graduação em Geociências, Universidade Federal do Rio Grande do Sul, Agronomia, Porto Alegre, Rio Grande do Sul, Brazil. CONICET-Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Buenos Aires, Argentina.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

31075140

Citation

Guignard, Morgan L., et al. "The Postcranial Anatomy of Brasilodon Quadrangularis and the Acquisition of Mammaliaform Traits Among Non-mammaliaform Cynodonts." PloS One, vol. 14, no. 5, 2019, pp. e0216672.
Guignard ML, Martinelli AG, Soares MB. The postcranial anatomy of Brasilodon quadrangularis and the acquisition of mammaliaform traits among non-mammaliaform cynodonts. PLoS One. 2019;14(5):e0216672.
Guignard, M. L., Martinelli, A. G., & Soares, M. B. (2019). The postcranial anatomy of Brasilodon quadrangularis and the acquisition of mammaliaform traits among non-mammaliaform cynodonts. PloS One, 14(5), e0216672. https://doi.org/10.1371/journal.pone.0216672
Guignard ML, Martinelli AG, Soares MB. The Postcranial Anatomy of Brasilodon Quadrangularis and the Acquisition of Mammaliaform Traits Among Non-mammaliaform Cynodonts. PLoS One. 2019;14(5):e0216672. PubMed PMID: 31075140.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The postcranial anatomy of Brasilodon quadrangularis and the acquisition of mammaliaform traits among non-mammaliaform cynodonts. AU - Guignard,Morgan L, AU - Martinelli,Agustin G, AU - Soares,Marina B, Y1 - 2019/05/10/ PY - 2019/01/25/received PY - 2019/04/25/accepted PY - 2019/5/11/entrez PY - 2019/5/11/pubmed PY - 2020/1/18/medline SP - e0216672 EP - e0216672 JF - PloS one JO - PLoS One VL - 14 IS - 5 N2 - Brasilodon quadrangularis (Cynodontia, Probainognathia) is an iconic non-mammaliaform cynodont from the Late Triassic of Brazil (Riograndia Assemblage Zone, Candelária Sequence), being considered as the sister taxon of Mammaliaformes. Although its phylogenetic position is very important, several aspects of its postcranial anatomy remain unclear or unstudied. Here, we present a detailed description of the postcranial elements referred to Brasilodon, including previously mentioned specimens and new ones, which add relevant information about its postcranial morphology and provide a new insight into the anatomical transition between advanced non-mammaliaform cynodonts and early mammaliaforms. Functional and ecological implications are also investigated, based on the postcranial morphology and muscular reconstructions. The postcranium of Brasilodon differs from most non-mammaliaform cynodonts and presents similarities with tritylodontids, early mammaliaforms and extant therians, such as a ventrally oriented scapular glenoid facet, a distinct and ossified greater humeral tubercle, lack of ectepicondylar foramen, olecranon process, hemispherical humeral and femoral heads and a prominent intertrochanteric crest. The humeral torsion, the length of the deltopectoral crest, the large bicipital groove and the well-developed lesser tubercle, indicate that the forelimb of Brasilodon was hold in a semi-sprawling position, with well-developed adductor muscles to maintain the body off the ground. The short femoral neck and the strong medial projection of the femoral head indicate the femur was held in a more erect posture than in basal non-mammaliaform cynodonts. The anterodorsally projected iliac blade with reduced postacetabular process, reduction of the anterior part of the pubis, medially located lesser trochanter indicate a basically mammalian pattern of pelvic musculature, able to swing the femur in a nearly parasagittal plane. SN - 1932-6203 UR - https://www.unboundmedicine.com/medline/citation/31075140/The_postcranial_anatomy_of_Brasilodon_quadrangularis_and_the_acquisition_of_mammaliaform_traits_among_non_mammaliaform_cynodonts_ DB - PRIME DP - Unbound Medicine ER -