In:
Biological Journal of the Linnean Society, Oxford University Press (OUP), ( 2019-07-05)
Abstract:
Pareiasaurs were one of the main clades of large herbivorous tetrapods in Middle–Late Permian continental ecosystems. Despite abundant pareiasaur material, many aspects of their biology remain poorly known. This paper provides a description of ontogenetic changes in long-bone and rib microanatomy/histology of two Upper Permian pareiasaurs from Russia, Deltavjatia rossica and Scutosaurus karpinskii. Analysis of a growth series of bones of Deltavjatia and Scutosaurus revealed rapid and cyclical growth early in ontogeny (as indicated by fast-growing fibrolamellar bone with lines of arrested growth). This was followed by a change in the growth pattern (as indicated by an outer avascular layer of lamellar bone in the cortex) and a decrease in the growth rate after 50% of maximum body size was reached in Deltavjatia and 75% in Scutosaurus (larger body sizes in Scutosaurus were attained through an extended initial period of fast skeletal growth). The study confirms that the bones of all pareiasaurs are histologically and microanatomically uniform [spongious (porous) microstructure and a very thin compact cortex] and indicate a similar growth strategy (a short initial period of rapid and cyclical growth followed by a long period of slow growth). The microanatomical characteristics of pareiasaurs do not provide a clear indication of their lifestyle.
Type of Medium:
Online Resource
ISSN:
0024-4066
,
1095-8312
DOI:
10.1093/biolinnean/blz094
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2019
detail.hit.zdb_id:
1461865-5
detail.hit.zdb_id:
220623-7
SSG:
12
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