Bone Histology Reveals a High Environmental and Metabolic Plasticity as a Successful Evolutionary Strategy in a Long-Lived Homeostatic Triassic Temnospondyl
2013 (English)In: Evolutionary biology, ISSN 0071-3260, E-ISSN 1934-2845, Vol. 40, no 4, 627-647 p.Article in journal (Refereed) Published
Evolutionary stasis (long-term stability of morphology in an evolving lineage) is a pattern for which explanations are usually elusive. The Triassic tetrapod Gerrothorax pulcherrimus, a gill-bearing temnospondyl, survived for 35 million years in the Germanic Basin of Central Europe persisting throughout the dinosaur-dominated Late Triassic period. This evolutionary stasis coincides with the occurrence of this species in a wide range of habitats and environmental conditions. By the combination of palaeoecological and palaeohistological analyses, we found great ecological flexibility in G. pulcherrimus and present substantial evidence of developmental and metabolic plasticity despite the morphological stasis. We conclude that G. pulcherrimus could show the capacity to settle in water bodies too harsh or unpredictable for most other tetrapods. This would have been made possible by a unique life history strategy that involved a wide reaction norm, permitting adjustment to fluctuating conditions such as salinity and level of nutrients. Growth rate, duration of juvenile period, age at maturity, and life span were all subject to broad variation within specimens of G. pulcherrimus in one single lake and in between different lakes. In addition to providing a better understanding of fossil ecosystems, this study shows the potential of such a methodology to encourage palaeobiologists and evolutionary biologists to consider the mechanisms of variation in extant and fossil organisms by using a similar time-scope reference.
Place, publisher, year, edition, pages
2013. Vol. 40, no 4, 627-647 p.
Morphological stasis, Developmental plasticity, Reaction norm, Environmental canalization
IdentifiersURN: urn:nbn:se:uu:diva-213310DOI: 10.1007/s11692-013-9238-3ISI: 000327126200015OAI: oai:DiVA.org:uu-213310DiVA: diva2:682159