Long-bone development and life-history traits of the Devonian tristichopterid Hyneria lindae

Abstract

Hyneria lindae is one of the largest Devonian sarcopterygians. It was found in the Catskill Formation (late Famennian) of Pennsylvania, USA. The current study focuses on the palaeohistology of the humerus of this tristichopterid and supports a low ossification rate and a late ossification onset in the appendicular skeleton. In addition to anatomical features, the large size of the cell lacunae in the cortical bone of the humerus mid-shaft may suggest a large genome size and associated neotenic condition for this species, which could, in turn, be a partial explanation for the large size of H. lindae. The low metabolism of H. lindae revealed here by bone histology supports the hypothesis of an ambush predatory behaviour. Finally, the lines-of-arrested-growth pattern and late ossification of specimen ANSP 21483 suggest that H. lindae probably had a long juvenile stage before reaching sexual maturity. Although very few studies address the life-history traits of stem tetrapods, they all propose a slow limb development for the studied taxa despite different ecological conditions and presumably distinct behaviours. The bone histology of H. lindae would favour the hypothesis that a slow long-bone development could be a general character for stem tetrapods.

Three‐dimensional characterization of osteocyte volumes at multiple scales, and its relationship with bone biology and genome evolution in ray‐finned fishes

“…Tomography acquisition was done with a set‐up producing volumes with an isotropic voxel size of 0.7 µm. This voxel size has been empirically shown to be adequate for segmenting and measuring osteocyte lacunae in SRµCT virtual palaeohistology (Kamska et al, 2019; Sanchez et al, 2012, 2013, 2014). In order to accommodate the different sizes and densities of our specimens, we used four different set‐ups to acquire data (Appendix S1), changing the energy (detected energies of 19, 35, 105 and 112 keV, respectively) to adjust the transmission and the dose intake of the sample and to avoid movement during the scans (exposure to the beam could cause deformation of the sample in some of the set‐ups we tried).…”

“…van Hove et al, 2009; Vatsa et al, 2008), serial focused ion beam and serial block‐face scanning electron microscopy (e.g. Schneider, Meier,Wepf, & Müller, 2010), ptychographic X‐ray computed tomography (Dierolf et al, 2010) and X‐ray synchrotron micro‐computed tomography (SRµCT) or nanotomography (Currey & Shahar, 2013; Dong et al, 2014; Kamska et al, 2019; Mader, Schneider, Müller, & Stampanoni, 2013; O’Shea, Keating, & Donoghue, 2019; Ofer et al, 2019; Pacureanu, Langer, Boller, Tafforeau, & Peyrin, 2012; Peyrin, Dong, Pacureanu, & Langer, 2014; Sanchez et al, 2013, 2014; Sanchez, Tafforeau, Clack, & Ahlberg, 2016; Schneider et al, 2007; Suniaga et al, 2018), each method bringing comparative advantages and shortcomings (Goggin, Zygalakis, Oreffo, & Schneider, 2016; Sanchez, Ahlberg, Trinajstic, Mirone, & Tafforeau, 2012; Webster et al, 2013).…”

Three-dimensional characterisation of osteocyte volumes at multiple scales, and its relationship with bone biology and genome evolution in ray-finned fishes

“…LAGs are often visible in SRµCT images (e.g. Sanchez et al, 2016;Kamska et al, 2018). Cell-volume variation is associated with this cyclical pattern in sarcopterygians (Castanet et al, 1993;Sanchez et al, 2014).…”

“…Finally, with a few exceptions (e.g. Kölliker, 1859;Stéphan, 1900;Amprino & Godina, 1956;Meunier, 1989;Meunier & Huysseune, 1992;Sanchez et al, 2014;Kamska et al, 2018;Davesne et al, 2019;Ofer et al, 2019), inter-specific comparisons of osteocyte morphology have been made only on tetrapods (four-limbed terrestrial vertebrates), representing only a subset of vertebrate diversity.…”

“…A small, but growing number of bone histological studies are based on highresolution 3D imaging. Various methods have been used to three-dimensionally visualise osteocytes and/or their canalicular network, including confocal laser scanning microscopy (e.g., Vatsa et al, 2008;van Hove et al, 2009), serial focused ion beam and serial block-face scanning electron microscopy (e.g., Schneider et al, 2010), ptychographic X-ray computed tomography (Dierolf et al, 2010) and synchrotron Xray micro-(SR-µCT) or nanotomography (Schneider et al, 2007;Pacureanu et al, 2012;Currey & Shahar, 2013;Mader et al, 2013;Sanchez et al, 2013Sanchez et al, , 2014Sanchez et al, , 2016Dong et al, 2014;Peyrin et al, 2014;Suniaga et al, 2018;Kamska et al, 2018;O'Shea et al, 2019;Ofer et al, 2019), each method bringing comparative advantages and shortcomings (Sanchez et al, 2012;Webster et al, 2013;Goggin et al, 2016).…”