Cats in the forest: predicting habitat adaptations from humerus morphometry in extant and fossil Felidae (Carnivora)

Abstract

Mammalian carnivores are rarely incorporated in paleoenvironmental reconstructions, largely because of their rarity within the fossil record. However, multivariate statistical modeling can be successfully used to quantify specific anatomical features as environmental predictors. Here we explore morphological variability of the humerus in a closely related group of predators (Felidae) to investigate the relationship between morphometric descriptors and habitat categories. We analyze linear measurements of the humerus in three different morphometric combinations (log-transformed, size-free, and ratio), and explore four distinct ways of categorizing habitat adaptations. Open, Mixed, and Closed categories are defined according to criteria based on traditional descriptions of species, distributions, and biome occupancy. Extensive exploratory work is presented using linear discriminant analyses and several fossils are included to provide paleoecological reconstructions.We found no significant differences in the predictive power of distinct morphometric descriptors or habitat criteria, although sample splitting into small and large cat guilds greatly improves the stability of the models. Significant insights emerge for three long-canine cats: Smilodon populator, Paramachairodus orientalis, and Dinofelis sp. from Olduvai Gorge (East Africa). S. populator and P. orientalis are both predicted to have been closed-habitat adapted taxa. The false “sabertooth” Dinofelis sp. from Olduvai Gorge is predicted to be adapted to mixed habitat. The application of felid humerus ecomorphology to the carnivoran record of Olduvai Gorge shows that the older stratigraphic levels (Bed I, 1.99–1.79 Ma) included a broader range of environments than Beds II or V, where there is an abundance of cats adapted to open environments.

Quaternary mammals from central Brazil (Serra da Bodoquena, Mato Grosso do Sul) and comments on paleobiogeography and paleoenvironments

“…Bocherens et al (2016) suggested that S. populator predominantly hunted prey in open environments, behaving as a social predator. However, ecomorphological studies have indicated that these great felines were also adapted to forests (Meloro et al, 2013).…”

Occurrence and morphometrics of the brachioradialis muscle in wild carnivorans (Carnivora: Caniformia, Feliformia)

“…Since thoracic limbs are not only used in locomotion, but also in prey capture and grooming and mating behavior, their morphology can be a good predictor of numerous ecological variables, such as the size and kind of prey, the variety of movements, the role in supporting body mass (ANDERSSON 2004a, FABRE et al 2013a) and the habitat (DAVIS 1964, EWER et al 1973, TAYLOR 1989, POLLY 2007, MEACHEN-SAMUELS & VAN-VALKENBURGH 2009, FABRE et al 2013a, et al 2013b, MELORO et al 2013, MARTÍN-SERRA et al 2014. Together with cranio-dental data, data on thoracic limbs are also used to extrapolate the predatory behavior of extinct species (IWANIUK et al 1999, ANDERSSON & WERDELIN 2003.…”

Bovid ecomorphology and hominin paleoenvironments of the Shungura Formation, lower Omo River Valley, Ethiopia

“…This indicated that our analysis is driven by morphology influenced by habitat constraints, and that the DFA is appropriate for ecomorphological analyses seeking to allocate unknown fossil elements to habitat type using astragali. This analysis provides support for an increasing body of work suggesting that although allometry and shared ancestry will influence an organism"s phenotype, this phenotype will also be impacted by the environmental constraints under which the organism has to live (Plummer et al, 2008;Walmsley et al, 2012;Meloro et al, 2013;Barr, 2014). Plummer et al / 23 Fossil astragali For the 4-habitat model, the DFA developed using the modern astragali was used to classify fossil astragali from the Shungura Formation (Supplementary Material, S1).…”