Mammalian bone palaeohistology: a survey and new data with emphasis on island forms

Abstract

The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of Japan closely related to Megaloceros, indicate a high growth rate. These examples and the synthesis of existing data show the potential of bone microstructure to reveal essential information on life history evolution. The bone tissue and the skeletochronological data of the sampled island species suggest the presence of various modes of bone histological modification and mammalian life history evolution on islands to depend on factors of island evolution such as island size, distance from mainland, climate, phylogeny, and time of evolution.

Calibration of life history traits with epiphyseal closure, dental eruption and bone histology in captive and wild red deer

“…In the case of the tibiae, significant differences were not found between subspecies, either in total growth areas (P = 0.617) or in single areas. We calculated the growth rates for each growth zone both for tibia and femur using bone growth areas, instead of distance between BGMs (Mar ın- Moratalla et al 2013Moratalla et al , 2014Kolb et al 2015b;Jordana et al 2016). It is important to highlight that specimens from Lleida exhibited a different growth pattern than the other two populations, both in femora ( Fig.…”

Bone cortical compactness in ‘tree sloths’ reflects convergent evolution

“…Bone remodeling is a lifelong process that influences bone structure until the oldest ages (Amprino & Godina, 1947). Intensity of remodeling and the resulting secondary osteons density varies among mammals, from no osteons at their long bone midshaft to a large number of them, which form in the latter case dense Haversian tissue (Kolb et al 2015). Studies on human long bones indicate that young, growing individuals (before ca.…”

Palaeobiological inferences based on long bone epiphyseal and diaphyseal structure - the forelimb of xenarthrans (Mammalia)

“…Nevertheless, the fact that some analyses successfully distinguished ecological groups might indicate that broad differences of bone structure among lifestyles can exceed, at least in some cases, individual variability. Because fossil bone cross-sections at mid-diaphysis have been produced for over a century and a half (Kolb et al 2015), a large number of mid-diaphyseal data related to extinct taxa have been acquired, and successfully exploited for palaeobiological inferences (e.g., Germain & Laurin, 2005). Fossil three-dimensional (3D) trabecular architecture has been much less investigated, as, to our knowledge, only few studies have been published, which are all focussing on primates (DeSilva & Devlin 2012; Barak et al 2013;Su et al 2013;Skinner et al 2015;Su & Carlson 2017;Ryan et al 2018).…”