Locomotor correlates of the scapholunar of living and extinct carnivorans

Abstract

The relationship of carpal morphology to ecology and habitat is under studied in carnivorans and more generally in mammals. Here, we use 3D‐scanning techniques to assess the usefulness of a carpal bone, the scapholunar, in carnivorans to reflect ecology and habitat, and to reconstruct the ecology of five extinct carnivorans from two fossil sites: Rancho La Brea and Natural Trap Cave. We 3D‐scanned scapholunars and measured articular surface areas and angles between articular facets using GeoMagic and Rhino 3D‐software. We analyzed the difference in these metrics using multivariate analysis of variance and discriminant function analysis. Results show that the scapholunar reflects ecological signal, with clear groupings of cursorial carnivorans and grappling/climbing carnivorans; however, phylogenetic signal was also present in the results with hyaenids, canids, and large felids in distinct morphospaces. Extinct species Miracinonyx trumani (American cheetah) and Smilodon fatalis (sabertooth cat) showed surprising results with M. trumani grouping with pantherines instead of Acinonyx or Puma, suggesting it runs but still retains the ability to grapple prey. S. fatalis groups with pantherines, but also shows some unique adaptations, suggesting it had a different range of wrist motion than living cats. Overall, the scapholunar is a good indicator of ecology and functional morphology and can be another tool to use in modern and fossil carnivorans to reconstruct extinct ecologies and locomotor behaviors.

Postcranial elements of small mammals as indicators of locomotion and habitat

“…The most common taxa of interest have been primates (e.g., Szalay & Dagosto, 1980;Rose, 1988Rose, , 1989Rose, , 1994Gebo & Sargis, 1994;Godfrey et al, 1997;Schmitt, 2003;Youlatos, 2003;Dunn et al, 2016;Elton, 2002;Elton et al, 2016;Arias-Martorell, 2018-this is but a small sample of the voluminous primate literature); carnivorous mammals (Taylor, 1974(Taylor, , 1976Van Valkenburgh, 1987;Gebo & Rose, 1993;Iwaniuk, Pellis & Whishaw, 1999;Schutz & Guralnick, 2007;Polly & MacLeod, 2008;Meachen-Samuels & Van Valkenburgh, 2009;Walmsley et al, 2012;Fabre et al, 2013;Meloro et al, 2013;Janis & Figueirido, 2014;Martín-Serra, Figueirido & Palmqvist, 2014a, 2014bFabre et al, 2015aFabre et al, , 2015bErcoli & Youlatos, 2016;Panciroli et al, 2017;Dunn et al, 2019;Meloro & De Olivera, 2019;Tarquini, 2019); and rodents (Elissamburu & Vizcaíno, 2004;Weisbecker & Schmid, 2006;Dunn & Rasmussen, 2007;Samuels & Van Valkenburgh, 2008;Morgan, 2009;Mor...…”

“…The most common taxa of interest have been primates (e.g., Szalay & Dagosto, 1980 ; Rose, 1988 , 1989 , 1994 ; Gebo & Sargis, 1994 ; Godfrey et al, 1997 ; Schmitt, 2003 ; Youlatos, 2003 ; Dunn et al, 2016 ; Elton, 2002 ; Elton et al, 2016 ; Arias-Martorell, 2018 —this is but a small sample of the voluminous primate literature); carnivorous mammals ( Taylor, 1974 , 1976 ; Van Valkenburgh, 1987 ; Gebo & Rose, 1993 ; Iwaniuk, Pellis & Whishaw, 1999 ; Schutz & Guralnick, 2007 ; Polly & MacLeod, 2008 ; Meachen-Samuels & Van Valkenburgh, 2009 ; Walmsley et al, 2012 ; Fabre et al, 2013 ; Meloro et al, 2013 ; Janis & Figueirido, 2014 ; Martín-Serra, Figueirido & Palmqvist, 2014a , 2014b , 2016 ; Fabre et al, 2015a , 2015b ; Ercoli & Youlatos, 2016 ; Panciroli et al, 2017 ; Dunn et al, 2019 ; Meloro & De Olivera, 2019 ; Tarquini, 2019 ); and rodents ( Elissamburu & Vizcaíno, 2004 ; Weisbecker & Schmid, 2006 ; Dunn & Rasmussen, 2007 ; Samuels & Van Valkenburgh, 2008 ; Morgan, 2009 ; Morgan & Álvarez, 2013 ; Boivin et al, 2018 ; Calede, Samuels & Chen, 2019 ; Hedrick et al, 2020 ). Studies of other mammalian orders (excluding here larger mammals such as ungulates and large diprotodontid marsupials) include smaller marsupials ( Lemelin, 1999 ; Argot, 2001 , 2002 ; Szalay & Sargis, 2001 ; Weisbecker & Warton, 2006 ; Bassavora, Janis & Archer, 2009 ; Flores & Díaz, 2009 ; Warburton et al, 2011 ; ...…”

Trait-based paleontological niche prediction demonstrates deep time parallel ecological occupation in specialized ant predators

“…Across vertebrate species, limb anatomy is a predictor of locomotion, prey items, and substrate behaviour. In particular, the forelimb anatomy of carnivores has been used to predict the likely predatory habits and prey size of extinct carnivorous mammals and mammaliaforms (Dunn et al 2019; Ercoli et al 2012; Figueirido et al 2016; Jenkins et al 2020; Lungmus and Angielczyk 2021; Meloro and Louys 2014). Other examples of extant morphology used in the prediction of extinct ecology include estimating prey type in extinct raptor species from present-day birds of prey (Hertel 1995); predicting prey items and modes of scavenging in extinct crocodyliforms from extant crocodyliform snout morphology (Drumheller and Wilberg 2019); approximating arboreal behaviour in extinct primates (Rector and Vergamini 2018); and predicting habitat preferences in fossil Anolis lizards using ear canal shape (Dickson et al 2017).…”

Morphological evolution of the carnivoran sacrum

“…Similarly, the study of the appendicular skeleton has provided important evidence for understanding the influence of natural selection on long bone morphology related to predatory behaviour (Meachen‐Samuels and Van Valkenburgh, 2009b; Figueirido and Janis, 2011; Janis and Figueirido, 2014), habitat preference (Meloro et al ., 2013; Figueirido et al ., 2016), or locomotor strategies (e.g. Polly, 2008; Samuels et al ., 2013; Figueirido et al ., 2015; Panciroli et al ., 2017; Dunn et al ., 2019). These approaches have allowed the inference of locomotor strategies in a wide array of extinct carnivores (Samuels et al ., 2013; Figueirido et al ., 2015; Martín‐Serra et al ., 2016; Panciroli et al ., 2017; Dunn et al ., 2019).…”

“…Polly, 2008; Samuels et al ., 2013; Figueirido et al ., 2015; Panciroli et al ., 2017; Dunn et al ., 2019). These approaches have allowed the inference of locomotor strategies in a wide array of extinct carnivores (Samuels et al ., 2013; Figueirido et al ., 2015; Martín‐Serra et al ., 2016; Panciroli et al ., 2017; Dunn et al ., 2019).…”