Stéphane Peigné

Predormancy omnivory in European cave bears evidenced by a dental microwear analysis of Ursus spelaeus from Goyet, Belgium

Previous morphological and isotopic studies indicate that Late Pleistocene cave bear (Ursus spelaeus) diet ranged from mostly vegetarian to omnivory or even carnivory. However, such analyses do not provide information on seasonal diets, and only provide an average record of diet. A dental microwear analysis of 43 young and adult individuals demonstrate that, during the predormancy period, cave bears from Goyet (Late Pleistocene, Belgium) were not strictly herbivorous, but had a mixed diet composed of hard items (e.g., possibly bone), invertebrates (e.g., insects), meat (ungulates, small vertebrates), and/or plant matter (hard mast, seeds, herbaceous vegetations, and fruits). Therefore, our results indicate that cave bears at Goyet were generalist omnivores during the predormancy period, which is consistent with current data on the dietary ecology of extant bears during this season. These data also raise questions about the ecological role and causes of the extinction of cave bears.

Anthropoid versus strepsirhine status of the African Eocene primates Algeripithecus and Azibius: craniodental evidence.

Recent fossil discoveries have demonstrated that Africa and Asia were epicentres for the origin and/or early diversification of the major living primate lineages, including both anthropoids (monkeys, apes and humans) and crown strepsirhine primates (lemurs, lorises and galagos). Competing hypotheses favouring either an African or Asian origin for anthropoids rank among the most hotly contested issues in paleoprimatology. The Afrocentric model for anthropoid origins rests heavily on the >45 Myr old fossil Algeripithecus minutus from Algeria, which is widely acknowledged to be one of the oldest known anthropoids. However, the phylogenetic position of Algeripithecus with respect to other primates has been tenuous because of the highly fragmentary fossils that have documented this primate until now. Recently recovered and more nearly complete fossils of Algeripithecus and contemporaneous relatives reveal that they are not anthropoids. New data support the idea that Algeripithecus and its sister genus Azibius are the earliest offshoots of an Afro–Arabian strepsirhine clade that embraces extant toothcombed primates and their fossil relatives. Azibius exhibits anatomical evidence for nocturnality. Algeripithecus has a long, thin and forwardly inclined lower canine alveolus, a feature that is entirely compatible with the long and procumbent lower canine included in the toothcomb of crown strepsirhines. These results strengthen an ancient African origin for crown strepsirhines and, in turn, strongly challenge the role of Africa as the ancestral homeland for anthropoids.

Getting a grip on the evolution of grasping in musteloid carnivorans: a three-dimensional analysis of forelimb shape.

The ability to grasp and manipulate is often considered a hallmark of hominins and associated with the evolution of their bipedal locomotion and tool use. Yet, many other mammals use their forelimbs to grasp and manipulate objects. Previous investigations have suggested that grasping may be derived from digging behaviour, arboreal locomotion or hunting behaviour. Here, we test the arboreal origin of grasping and investigate whether an arboreal lifestyle could confer a greater grasping ability in musteloid carnivorans. Moreover, we investigate the morphological adaptations related to grasping and the differences between arboreal species with different grasping abilities. We predict that if grasping is derived from an arboreal lifestyle, then the anatomical specializations of the forelimb for arboreality must be similar to those involved in grasping. We further predict that arboreal species with a well‐developed manipulation ability will have articulations that facilitate radio‐ulnar rotation. We use ancestral character state reconstructions of lifestyle and grasping ability to understand the evolution of both traits. Finally, we use a surface sliding semi‐landmark approach capable of quantifying the articulations in their full complexity. Our results largely confirm our predictions, demonstrating that musteloids with greater grasping skills differ markedly from others in the shape of their forelimb bones. These analyses further suggest that the evolution of an arboreal lifestyle likely preceded the development of enhanced grasping ability.

Implications of the functional anatomy of the hand and forearm of Ailurus fulgens (Carnivora, Ailuridae) for the evolution of the ‘false-thumb’ in pandas

Both the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) possess a ‘false‐thumb’, actually an enlarged radial sesamoid bone, which contributes to the gripping action of the hand. These species are not closely related, however, as one is an ursid and the other an ailurid, so the fact that they share this adaptation implies a remarkable convergence. We studied the functional anatomy of this structure in the red panda, comparing it with existing descriptions of the grasping mechanism in both pandas. Previous interpretations of the radial sesamoid in Ailurus as a rod‐like structure without direct articulation to the wrist bones are inaccurate. There are various important differences between the red panda and the giant panda. In the former, the lesser development of the radial sesamoid, its connection with the flexor retinaculum, the presence of an insertion of the muscle abductor pollicis longus in the first metacarpal, which enhances its supinatory action, and the presence of a muscle flexor brevis digitorum manus point to thin‐branch climbing features serving as an exaptation to the more recent role of the red panda hand in the manipulation of bamboo.

Do constraints associated with the locomotor habitat drive the evolution of forelimb shape? A case study in musteloid carnivorans

Convergence in morphology can result from evolutionary adaptations in species living in environments with similar selective pressures. Here, we investigate whether the shape of the forelimb long bones has converged in environments imposing similar functional constraints, using musteloid carnivores as a model. The limbs of quadrupeds are subjected to many factors that may influence their shape. They need to support body mass without collapsing or breaking, yet at the same time resist the stresses and strains induced by locomotion. This likely imposes strong constraints on their morphology. Our geometric morphometric analyses show that locomotion, body mass and phylogeny all influence the shape of the forelimb. Furthermore, we find a remarkable convergence between: (i) aquatic and semi‐fossorial species, both displaying a robust forelimb, with a shape that improves stability and load transfer in response to the physical resistance imposed by the locomotor environment; and (ii) aquatic and arboreal/semi‐arboreal species, with both groups displaying a broad capitulum. This augments the degree of pronation/supination, an important feature for climbing as well as grasping and manipulation ability, behaviors common to aquatic and arboreal species. In summary, our results highlight how musteloids with different locomotor ecologies show differences in the anatomy of their forelimb bones. Yet, functional demands for limb movement through dense media also result in convergence in forelimb long‐bone shape between diverse groups, for example, otters and badgers.

New Oligocene vertebrate localities from Northern Kenya (Turkana basin)

STÉPHANE DUCROCQ,*,1 JEAN-RENAUD BOISSERIE,1 JEAN-JACQUES TIERCELIN,2 CYRILLE DELMER,3 GÉRALDINE GARCIA,1 MANTHI FREDERICK KYALO,4 MEAVE G. LEAKEY,5 LAURENT MARIVAUX,6 OLGA OTERO,1 STÉPHANE PEIGNÉ,7 PASCAL TASSY,7 and FABRICE LIHOREAU6; 1IPHEP, UMR CNRS 6046, Faculté des Sciences de Poitiers, 40 avenue du Recteur Pineau, F-86022 Poitiers cedex, France, stephane.ducrocq@univ-poitiers.fr, geraldine.garcia@univ-poitiers.fr, olga.otero@univ-poitiers.fr; jean.renaud.boisserie@univ-poititers.fr; 2UMR CNRS 6118 Géosciences Rennes, Université de Rennes 1, Campus de Beaulieu, Bât. 15, F-35042 Rennes cedex, France, jean-jacques.tiercelin@ univ-rennes1.fr; 3Palaeontology Department, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom; 4Palaeontology Section, NMK HQ Museum Hill, P.O. Box 40658, 00100, Nairobi, Kenya, fkmanthi@museums.or.ke; 5Stony Brook University, Turkana Basin Institute, N511 Social and Behavioral Sciences, Stony Brook, New York 11794-4364, U.S.A, meave.leakey@stonybrook.edu; 6ISEM, UMR CNRS 5554, Université Montpellier II, c.c. 064, Place Eugène Bataillon, F-34095 Montpellier cedex 5, France, Laurent.Marivaux@univ-montp2.fr, fabrice.lihoreau@univ-montp2.fr; 7UMR CNRS 7207, Muséum national d’Histoire naturelle, 8, rue Buffon CP 38, F-75231 Paris cedex 05, France, peigne@mnhn.fr; ptassy@mnhn.fr

EOCENE NIMRAVID CARNIVORANS FROM THAILAND

Abstract Dental remains assigned to nimravid carnivores have been discovered in southern Thailand. These specimens come from the upper Eocene Krabi Basin that has already yielded numerous vertebrate taxa important for the knowledge of mammal evolution. The fossils described here are among the oldest remains belonging to the Nimravidae, and they are attributed to Nimravus cf. intermedius and Hoplophoneus sp. The occurrence of nimravid carnivores in Southeast Asia implies exchanges between Asia and North America during the Late Eocene, and it supports a larger geographical distribution and an origin of the family older than previously known.

Systematics and phylogeny of the small felines (Carnivora, Felidae) from the Late Miocene of Europe: a new species of Felinae from the Vallesian of Batallones (MN 10, Madrid, Spain)

The Spanish fossil localities of Batallones-1 and Batallones-3 are two Vallesian (Late Miocene) natural traps known for their high concentration of carnivoran mammals. These include amphicyonids, ailurids, mustelids, ursids, hyaenids, machairodont felids, and two species of small-bodied felines, one the size of an European wildcat, Felis sylvestris, and the other the size of a caracal, Caracal caracal. Although these felines are much less abundant at the sites than their larger relatives, the sabre-toothed felids, the available samples from Batallones-1 and Batallones-3 are rich; they include postcranial elements, skulls and mandibles of the smaller species, while the larger feline species is solely known from postcranial elements recorded at Batallones-1. The small feline from Batallones-1 and Batallones-3, although showing similarities with the Turolian felines, is more related to the Middle Miocene genus Styriofelis Kretzoi, 1929, and thus we propose for it the new species name Styriofelis vallesiensis. On the other hand, the new generic name Pristifelis is proposed for the species Felis attica, which shows important differences with extant Felis.

THE AUDITORY REGION AND NASAL CAVITY OF OLIGOCENE NIMRAVIDAE (MAMMALIA: CARNIVORA)

Abstract Highly detailed microscopic preparation of both newly discovered and previously undescribed nimravine crania from the White River Group of North America reveals hitherto unreported morphological features of the basicranium and auditory region, particularly the composition of the auditory bulla and form of the petrosal. The monophyly of Dinictis, Hoplophoneus, and Nimravus is supported by a remarkably uniform configuration of the auditory bulla: (1) the form and placement of the entotympanics; (2) a near-vertical ectotympanic with elaborate styliform process partially enclosing the Eustachian tube; and (3) an anterior bulla wall formed by a unique overlap of the anterior entotympanic lamina by the elongate styliform process. Although an intact auditory bulla is unknown in an Eurasian nimravine, the auditory regions of the species represented by crania (Eusmilus bidentatus and Nimravus cf. intermedius from Quercy) demonstrate a definite affinity with New World genera, affirming the Holarctic distribution of the Nimravinae. In addition to identifying basicranial similarities among nimravines, we describe the first largely intact turbinate bones within the nasal cavity of a nimravid. CT (computed tomography) scanning of nimravid rostra reveals differing configurations of the maxilloturbinate in Dinictis and Hoplophoneus, the former more derived than the latter. Compared to other Carnivora, nimravid maxilloturbinates are most similar to those of living aeluroids, which are confined to the ventral part of the anterior nasal cavity. Nimravids lack the elaborately branching (dendrolamellar) maxilloturbinates of arctoid and cynoid carnivorans.

Testing for Depéret's Rule (Body Size Increase) in Mammals using Combined Extinct and Extant Data

Whether or not evolutionary lineages in general show a tendency to increase in body size has often been discussed. This tendency has been dubbed “Copes rule” but because Cope never hypothesized it, we suggest renaming it after Depéret, who formulated it clearly in 1907. Depérets rule has traditionally been studied using fossil data, but more recently a number of studies have used present-day species. While several paleontological studies of Cenozoic placental mammals have found support for increasing body size, most studies of extant placentals have failed to detect such a trend. Here, we present a method to combine information from present-day species with fossil data in a Bayesian phylogenetic framework. We apply the method to body mass estimates of a large number of extant and extinct mammal species, and find strong support for Depérets rule. The tendency for size increase appears to be driven not by evolution toward larger size in established species, but by processes related to the emergence of new species. Our analysis shows that complementary data from extant and extinct species can greatly improve inference of macroevolutionary processes.