Palaeoecological deductions from osteohistology

Abstract

Palaeoecological deductions are vital for understanding the evolution and diversification of species within prehistoric environments. This review highlights the multitude of ways in which the microanatomy and microscopic structure of bones enables palaeoecological deductions. The occurrence of growth marks in bones is discussed, and their usefulness in deducing the ontogenetic status and age of individuals is considered, as well as how such marks in bones permit the assessment of the growth dynamics of individuals and species. Here osteohistology is shown to provide insight into the structure of past populations, as well as ecological relationships between individuals. In addition, the response of bones to trauma, disease and moulting is considered. Finally, I explore how osteohistology can give insight into ecomorphological adaptations, such as filter feeding, probe feeding and saltatorial locomotion. Methodological advances in three-dimensional microtomography and synchrotron scanning bodes well for future studies in osteohistology and despite some compromises in terms of tissue identity, circumvents the crucial issue of destructive analyses.

Ontogenetic and interelemental study of appendicular bones of Caiman latirostris Daudin, 1802 sheds light on osteohistological variability in crocodylians

“…Cyclical growth marks are features within the compacta of bone that represent annual changes in the rate of bone deposition, that is, alternating rapid rates of growth (the zone) followed by a decrease in osteogenesis (or the growth rate; the annulus), which is often accompanied by a complete cessation of growth (LAGs; e.g., Castanet et al, 1993;Chinsamy, 2023;Chinsamy-Turan, 2005;Francillon-Vieillot et al, 1990). In some species of crocodiles, the correlation between the cyclically formed growth marks and seasons has been verified, and it is known that the annulus and/or LAGs are formed during the unfavorable season (e.g., Crocodylus niloticus;…”

“…In general, crocodiles are considered to have relatively slow growth, characterized by alternating cycles of relatively higher and lower growth rates throughout their lives. Faster rates of growth have been reported in living and fossil crocodylians, such as juvenile and adult specimens (irrespective of whether they were captive, wild, or individuals with some pathology of Caiman yacare , Andrade et al, 2018; A. mississippiensis , Chabreck & Joanen, 1979; Horner et al, 2001; Padian et al, 2004; Rainwater et al, 2021; Reid, 1997a, 1997b; de Ricqlès et al, 2003; Roberts et al, 1988; Tumarkin‐Deratzian, 2007; Werning, 2013; Woodward et al, 2014; Crocodylus sp., Enlow, 1969; Crocodylus porosus Reid, 1984, Crocodylus niloticus , Chinsamy, 1991; Crocodylus johnstoni , Chinsamy & Hillenius, 2004; and Leidyosuchus , Padian et al, 2004). In the postcranial bones studied here, we observed the presence of WB in most of the juveniles and in the inner cortex of adults, which indicates a higher rate of bone formation during early stages of ontogeny.…”

“…Foote (1911) and Enlow and Brown (1956) were among the first to describe the histology of long bones and osteoderms of living crocodylians, and since then, numerous studies have been carried out on both, extant (e.g., Audije‐Gil et al, 2023; de Buffrénil, 1982; Chinsamy, 1991, 1993a, 1993b; Cubo et al, 2012; Erickson & Brochu, 1999; Hutton, 1986; Klein et al, 2009; Lee, 2004; Mascarenhas‐Junior et al, 2021; Rainwater et al, 2021; Tucker, 1997; Tumarkin‐Deratzian, 2007; Werning, 2013; Woodward et al, 2011, 2014), and extinct taxa of this group (e.g., Andrade & Sayão, 2014; Company & Pereda‐Suberbiola, 2017; Erickson & Brochu, 1999; Padian et al, 2004; Pellegrini et al, 2021; Sayão et al, 2016). It is noteworthy that, although studies on bone microstructure of Crocodylia are becoming more numerous, the diversity of species studied remains scarce.…”

“…In this regard, although much research has focused on the Alligatoridae clade (e.g., especially on Alligator mississippiensis Daudin, 1801; Klein et al, 2009; Lee, 2004; Tumarkin‐Deratzian, 2007; Woodward et al, 2011, 2014), few studies have been done on Caimaninae (Andrade et al, 2018; Mascarenhas‐Junior et al, 2021), and so far, only the study by Mascarenhas‐Junior et al (2021) focuses on the histology of humerus and rib of juveniles C. latirostris from Brazil. Also, although the osteohistology of living crocodiles has been reasonably well published, most of the works analyze either an ontogenetic series of a single bone element or numerous postcranial bones from single juvenile or subadult specimens of a particular species (e.g., Audije‐Gil et al, 2023; Chinsamy, 1991, 1993a, 1993b; Lee, 2004; Woodward et al, 2014), and currently there are no studies that have analyzed the overall osteohistological changes that occur in the skeleton during growth (see below).…”

“…These alternating periods of growth are evidenced by variations in the type of bone tissue and in the presence of growth marks (either line of arrested growth [LAGs], or LAGs associated with annuli; e.g., Andrade & Sayão, 2014; Chinsamy, 2023; Chinsamy‐Turan, 2005; Company & Pereda‐Suberbiola, 2017; Hutton, 1986; Klein et al, 2009; Lee, 2004; Peabody, 1961; de Ricqlès et al, 2003; Tucker, 1997; Tumarkin‐Deratzian, 2007; Wink et al, 1987; Woodward et al, 2011). Although the microstructure of long bones of crocodylians shows a preponderance of parallel‐fibered bone (PFB) (e.g., A. mississippiensis, Crocodylus niloticus Laurenti, 1768, Gavialis gangeticus [Gmelin, 1789], Dyrosaurid ; Chinsamy, 1991; Hutton, 1986; Lee, 2004; Padian et al, 2004; Peabody, 1961; Reid, 1990; Tucker, 1997; Woodward et al, 2011, 2014), the presence of woven bone (WB) and fibrolamellar bone (FLB) has been also observed in captive specimens, in sick individuals, and in wild juveniles and adults (e.g., Andrade et al, 2018; Chabreck & Joanen, 1979; Chinsamy, 1991; Enlow, 1969; Horner et al, 2001; Mascarenhas‐Junior et al, 2021; Reid, 1996; de Ricqlès et al, 2003; Tumarkin‐Deratzian, 2007; Werning, 2013; Woodward et al, 2014). The correlation between the organization of the bone matrix, growth dynamics, and environmental seasonality has been supported in different species of Crocodylia such as Alligator (Woodward et al, 2011, 2014), Crocodylus (Peabody, 1961; Hutton, 1986), Gavialis (de Buffrénil, 1982), and Caiman (Andrade et al, 2018).…”