Life-history strategies indicate live-bearing in Nothosaurus (Sauropterygia)

2019

Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)

2018

Bone tissue, microanatomy, and growth are studied in humeri of the pachypleurosaurs Dactylosaurus from the early Anisian of Poland and of aff. Neusticosaurus pusillus from the Lettenkeuper (early Ladinian) of southern Germany. Histology and modeled growth curves are compared to already published data of other pachypleurosaurs. Therefore, we herein established growth curves for Anarosaurus from the middle Anisian of Winterswijk (the Netherlands) and for pachypleurosaurs from the Anisian/Ladinian of the Alpine Triassic (i.e., Neusticosaurus spp. and Serpianosaurus). Humeri of Dactylosaurus, Anarosaurus, and aff. N. pusillus, all from the Germanic Basin, usually display an inner ring of (pre-)…

An enigmatic marine reptile, Hispaniasaurus cranioelongatus (gen. et sp. nov.) with nothosauroid affinities from the Ladinian of the Iberian Range (S…

2017

An incomplete skull of a marine reptile with an atypical elongation of the postorbital region is described. The find comes from the Muschelkalk facies (Cañete Formation) of the Villora section (Iberian Range, Cuenca Province, Spain), characterised by a shallow marine (intertidal) environment and dated as Ladinian in age. The small skull has a rectangular shape, lacking, as preserved, upper temporal openings and a parietal foramen. The upper temporal openings might be secondarily closed. However, the absence of a parietal foramen and squamosals in the preserved part and the incompleteness of the pterygoids make a posteriorly postponed location of the upper temporal openings also conceivable.…

Triassic nursery? Evidence of gregarious behavior in juvenile pseudosuchian archosaurs as inferred by humeral histology of Aetosaurus ferratus (Noria…

2022

Unique growth pattern of Metoposaurus diagnosticus krasiejowensis (Amphibia, Temnospondyli) from the Upper Triassic of Krasiejów, Poland

2013

Morphology and bone histology of femora, tibiae, and fibulae of the temnospondyl Metoposaurus diagnosticus krasiejowensis from the Upper Triassic locality of Krasiejow (Poland) are studied for the first time. The growth pattern of Metoposaurus as preserved in a small growth series of femora, shows a regular alternating sequence of fast and slow growth phases, which are interpreted as representing zones and annuli. The slow growth phases (annuli) of the inner and outer cortex as well as those of different specimens are of a regular broad thickness. Such broad annuli are so far unknown for any vertebrate and make the growth pattern for Metoposaurus unique. These slow growth phases always cont…

Growth patterns and life-history strategies in Placodontia (Diapsida: Sauropterygia)

2015

Placodontia is a clade of durophagous, near shore marine reptiles from Triassic sediments of modern-day Europe, Middle East and China. Although much is known about their primary anatomy and palaeoecology, relatively little has been published regarding their life history, i.e. ageing, maturation and growth. Here, growth records derived from long bone histological data of placodont individuals are described and modelled to assess placodont growth and life-history strategies. Growth modelling methods are used to confirm traits documented in the growth record (age at onset of sexual maturity, age when asymptotic length was achieved, age at death, maximum longevity) and also to estimate undocum…

Bone histology, microanatomy, and growth of the nothosauroid Simosaurus gaillardoti (Sauropterygia) from the Upper Muschelkalk of southern Germany/Ba…

2016

Abstract Simosaurus gaillardoti was a large eosauropterygian (Sauropterygia), a group of diverse diapsid marine reptiles. Its occurrence correlates to transgression phases in the Germanic Basin and a former morphological study hypothesized that Simosaurus was capable of sustained swimming. Microanatomical analysis of five long bones revealed functional differences between the humerus and femur but did not confirm sustained swimming in Simosaurus. It had certain active swimming abilities but – based on microanatomy – it was a less efficient swimmer when compared to contemporaneously living nothosaurs. Simosaurus grew with well-vascularized coarse parallel-fibred bone tissue. Growth marks app…

Data from: Life-history strategies indicate live-bearing in Nothosaurus (Sauropterygia)

2019

In Sauropterygia, a diverse group of Mesozoic marine reptiles, fossil evidence of viviparity (live‐bearing) only exists for Pachypleurosauria and Plesiosauria, and was assumed to also be the case for nothosaurs. Previous studies have successfully applied an extant squamate model to sauropterygian life‐history traits. In extant squamates, oviparity and viviparity are associated with differences in life‐history trait combinations. We establish growth curves for Nothosaurus specimens based on their humeral histology. We then analyse life‐history traits derived from these curves and compare inferred traits to those of modern squamates and pachypleurosaurs to assess their reproduction mode. We s…