Osteohistology of Late Triassic prozostrodontian cynodonts from Brazil

Autor: Agustín G. Martinelli, Marina Bento Soares, Jennifer Botha-Brink
Jazyk: angličtina
Rok vydání: 2018
Předmět:
0106 biological sciences
010506 paleontology
Histology
Brasilodon
Zoology
lcsh:Medicine
Prozostrodontia
010603 evolutionary biology
01 natural sciences
General Biochemistry
Genetics and Molecular Biology

Paleontología
Ciencias de la Tierra y relacionadas con el Medio Ambiente
purl.org/becyt/ford/1 [https]
purl.org/becyt/ford/1.5 [https]
Morganucodon
OSTEOHISTOLOGY
Brasilitherium
PROZOSTRODONTIA
NON-MAMMALIAFORM CYNODONTS
0105 earth and related environmental sciences
Crania
biology
Kryptobaatar
General Neuroscience
lcsh:R
Prozostrodon
Paleontology
Growth patterns
General Medicine
biology.organism_classification
PALEOBIOLOGY
Evolutionary Studies
Non-mammaliaform cynodonts
Osteohistology
Mammaliaformes
Paleobiology
General Agricultural and Biological Sciences
GROWTH PATTERNS
CIENCIAS NATURALES Y EXACTAS
Zdroj: PeerJ, Vol 6, p e5029 (2018)
CONICET Digital (CONICET)
Consejo Nacional de Investigaciones Científicas y Técnicas
instacron:CONICET
PeerJ
Popis: The Prozostrodontia includes a group of Late Triassic-Early Cretaceous eucynodonts plus the clade Mammaliaformes, in which Mammalia is nested. Analysing their growth patterns is thus important for understanding the evolution of mammalian life histories. Obtaining material for osteohistological analysis is difficult due to the rare and delicate nature of most of the prozostrodontian taxa, much of which comprises mostly of crania or sometimes even only teeth. Here we present a rare opportunity to observe the osteohistology of several postcranial elements of the basal prozostrodontid Prozostrodon brasiliensis, the tritheledontid Irajatherium hernandezi, and the brasilodontids Brasilodon quadrangularis and Brasilitherium riograndensis from the Late Triassic of Brazil (Santa Maria Supersequence). Prozostrodon and Irajatherium reveal similar growth patterns of rapid early growth with annual interruptions later in ontogeny. These interruptions are associated with wide zones of slow growing bone tissue. Brasilodon and Brasilitherium exhibit a mixture of woven-fibered bone tissue and slower growing parallel-fibered and lamellar bone. The slower growing bone tissues are present even during early ontogeny. The relatively slower growth in Brasilodon and Brasilitherium may be related to their small body size compared to Prozostrodon and Irajatherium. These brasilodontids also exhibit osteohistological similarities with the Late Triassic/Early Jurassic mammaliaform Morganucodon and the Late Cretaceous multituberculate mammals Kryptobaatar and Nemegtbaatar. This may be due to similar small body sizes, but may also reflect their close phylogenetic affinities as Brasilodon and Brasilitherium are the closest relatives to Mammaliaformes. However, when compared with similar-sized extant placental mammals, they may have grown more slowly to adult size as their osteohistology shows it took more than one year for growth to attenuate. Thus, although they exhibit rapid juvenile growth, the small derived, brasilodontid prozostrodontians still exhibit an extended growth period compared to similar-sized extant mammals.
Databáze: OpenAIRE