Locomotor evolution of <Emphasis Type="Italic">Mesopithecus</Emphasis> (Primates: Colobinae) from Greece: evidence from selected astragalar characters

This paper reports our investigations into functional aspects of the astragalus of four samples of the genus Mesopithecus from Greece. More particularly, it aims to infer substrate preferences of M. delsoni/pentelicus from the Middle Turolian site of Perivolaki (central Greece), M. pentelicus from the late Middle Turolian site of Pikermi (southern Greece), and M. cf. pentelicus and M. cf. monspessulanus from the Late Turolian site of Dytiko (northern Greece). For these purposes, selected astragalar functional features, such as trochlea wedging, proximal facet curvature, and head rotation were expressed as linear measurements on both fossil and selected extant colobines. The size-adjusted measurements were used for univariate comparisons as well as a multivariate principal components analysis. Both approaches revealed that the selected characters were able to discriminate between extant arboreal and semiterrestrial colobines, but all fossil forms presented mosaic morphology. Thus, the oldest representative, M. delsoni/pentelicus was reconstructed as mainly semiterrestrial. On the other hand, the astragalus of M. pentelicus appeared to reflect semiterrestrial habits with a moderate adaptation to arboreality. Similar habitus reconstruction was allocated to the more recent M. cf. pentelicus, whereas the sympatric and synchronous M. cf. monspessulanus showed semiterrestrial adaptations with a slight preference of terrestrial substrates. The results mainly conform to paleoenvironmental reconstructions of the fossiliferous localities and denote that Mesopithecus was mainly a semiterrestrial radiation throughout its evolutionary history, with differential rates of use between arboreal and terrestrial substrates. These adaptations could have promoted the dispersal of the genus throughout Eurasia during the latest Miocene and Early Pliocene.     

Calcaneal features of the Greek Miocene primate Mesopithecus pentelicus (Cercopithecoidea: Colobinae)

This paper investigates substrate preferences of the Greek Colobine Mesopithecus pentelicus WAGNER, from the Miocene of Pikermi, by examining selected functional features of the calcaneus that distinguish between arboreal and terrestrial Cercopithecidae. Mesopithecus possesses a relatively long proximal calcaneal region associated with a slightly low and wide surface for the insertion of m. triceps surae. These features approximate that of semi-terrestrial Cercopithecidae and would suggest terrestrial cursorial activities. On the other hand, the relatively long and narrow proximal calcaneo-astragalar facet, similar to that of most arboreal species, would provide ampler subtalar movements. The mosaic of these features implies a semi-terrestrial way of life and conforms to the savanna-woodland paleoenvironment of Pikermi, Greece. These features appear to be well associated with foot function and change of habitus and are used to examine scenarios of the evolutionary history of the Colobinae.     

Late Turolian Mesopithecus (Mammalia: Cercopithecidae) from Axios Valley (Macedonia,Greece): earliest presence of M. monspessulanus in Europe

The fossil mammal localities of the Axios Valley (Macedonia, Greece) yielded a rich collection of Mesopithecus remains, which were first described at the beginning of the 1990s. The late Turolian Dytiko localities include several specimens of Mesopithecus, which were originally separated in two size-related forms: the relatively larger-sized M. cf. or aff. pentelicus, and the relatively smaller-sized M. cf. monspessulanus. However, some Dytiko specimens were only partially described, or remained even undescribed because the cranium either was still in connection with the mandible or was markedly deformed. Later, careful cleaning of the materials and their revision based on larger comparative samples indicate that they represent two distinct species: the relatively larger-sized specimens belong to M. pentelicus, while the relatively smaller-sized ones to M. monspessulanus. The Dytiko M. pentelicus has slightly smaller dental dimensions compared to M. pentelicus from Pikermi, indicating a possible trend for size decrease. The Dytiko M. monspessulanus, although close to the typical form of this species, has somewhat larger dimensions. The semi-terrestrial M. pentelicus disappeared at the end of the Miocene, while some of its populations adapted to the wetter and more woody Pliocene habitats, finally giving origin to M. monspessulanus, whose elbow-joint indicates an arboreal lifestyle. M. monspessulanus was widely distributed in Europe, but its remains are very scarce and are all from the Pliocene. Some questionable indications for the presence of M. monspessulanus in the latest Miocene come from some Italian Messinian sites (Gravitelli, Baccinello V3), but this scenario still needs verification. However, even if its presence in some Italian localities was confirmed, the Dytiko M. monspessulanus nonetheless represents the earliest known occurrence of this species in Europe, as the Dytiko fauna is considered as latest Turolian (pre-Messinian, 7.0–6.0 Ma).     

The Hand of Cercopithecoides williamsi (Mammalia,Primates): Earliest Evidence for Thumb Reduction among Colobine Monkeys

Thumb reduction is among the most important features distinguishing the African and Asian colobines from each other and from other Old World monkeys. In this study we demonstrate that the partial skeleton KNM-ER 4420 from Koobi Fora, Kenya, dated to 1.9 Ma and assigned to the Plio-Pleistocene colobine species Cercopithecoides williamsi, shows marked reduction of its first metacarpal relative to the medial metacarpals. Thus, KNM-ER 4420 is the first documented occurrence of cercopithecid pollical reduction in the fossil record. In the size of its first metacarpal relative to the medial metacarpals, C. williamsi is similar to extant African colobines, but different from cercopithecines, extant Asian colobines and the Late Miocene colobines Microcolobus and Mesopithecus. This feature clearly links the genus Cercopithecoides with the extant African colobine clade and makes it the first definitive African colobine in the fossil record. The postcranial adaptations to terrestriality in Cercopithecoides are most likely secondary, while ancestral colobinans (and colobines) were arboreal. Finally, the absence of any evidence for pollical reduction in Mesopithecus implies either independent thumb reduction in African and Asian colobines or multiple colobine dispersal events out of Africa. Based on the available evidence, we consider the first scenario more likely.     

A cercopithecid primate from the late miocene of Molayan,Afghanistan, with remarks onMesopithecus

The first fossil primate discovered in Afghanistan comes from the Late Miocene of Molayan, Khurdkabul Basin. The materials consist of an almost-complete juvenile mandible and an isolated P₃. These two specimens do not significantly differ from thePikermi Mesopithecus pentelicus and are assigned to this species. The primate mandible from the Late Miocene of Maragheh, Iran, which has always been referred by all authors toM. pentelicus, differs from the Pikermi and Molayan materials. It must be assigned to another taxon, probably a new one. The geographic range ofM. pentelicus turns out to be considerably wider in view of the discovery of the species in Molayan, eastern Afghanistan.     

<Emphasis Type="Italic">Mesopithecus</Emphasis> (Primates,Cercopithecidae) from the turolian locality of Vathylakkos 2 (Macedonia,Greece)

Two skulls, two mandibles and some postcranials ofMesopithecus from the locality “Vathylakkos 2” of Axios Valley (Macedonia, Greece) enlarge our knowledge about the genus and its differentiation. The new material together with an old skull from the same locality is compared with the Pikermi, “Ravin des Zouaves 5” (Axios Valley), and Maramena (Serres basin) samples. It is concluded that the VathylakkosMesopithecus resemblesM. pentelicus from Pikermi, as wellM. delsoni from “Ravin des Zouaves 5” and it is referred asMesopithecus sp. aff.M. pentelicus. The biochronological age of “Vathylakkos 2” has been considered as MN 12, while recent magnetostratigraphic data indicate an age of about 7.5 Ma. This age confirms the position of the VathylakkosMesopithecus between Pikermi and “Ravin des Zouaves 5”. Some dental indices compared with those of the RecentCercopithecus suggest that the Vathylakkos sample is monospecific.      

A new terrestrial amphipod from tertiary amber deposits of Chiapas province,Southern Mexico

Transitroides morsei new genus, new species, is described from late Oligocene Early Miocene amber deposits of Chiapas Province from southern Mexico. This new taxon is the first known fossil member of the amphipod family Talitridae and superfamily Talitroidea. It appears intermediate between regional extant palustral (salt‐marsh) genera and fully terrestrial landhoppers of the genus Caribitroides. These beetle‐like crustaceans form a significant part of the forest‐floor leaf‐litter communities in some tropical parts of the globe. Extant terrestrial amphipods occur in south‐central Mexico and adjacent rain forest habitats in Central America and the Caribbean. Their occasional use of arboreal habitats in search for decaying organic matter, which serves as food, explains their occurrence in fossilized resin.     

Folivory or fruit/seed predation for Mesopithecus, an earliest colobine from the late Miocene of Eurasia?

Here we compare dental microwear textures from specimens of the fossil genus Mesopithecus (Cercopithecidae, Colobinae) from the late Miocene of Eastern Europe with dental microwear textures from four extant primate species with known dietary differences. Results indicate that the dental microwear textures of Mesopithecus differ from those of extant leaf eaters Alouatta palliata and Trachypithecus cristatus and instead resemble more closely those of the occasional hard-object feeders Cebus apella and Lophocebus albigena. Microwear texture data presented here in combination with results from previous analyses suggest that Mesopithecus was a widespread, opportunistic feeder that often consumed hard seeds. These data are consistent with the hypothesis that early colobines may have preferred hard seeds to leaves.     

Hominoid phalanges from the middle Miocene site of Paşalar, Turkey

Eleven proximal and ten intermediate partial or complete hominoid phalanges have been recovered from the middle Miocene site of Pa?alar in Turkey. Based on species representation at Pa?alar, it is likely that most or all of the phalanges belong to Griphopithecus alpani rather than Kenyapithecus kizili, but both species may be represented. All of the complete or nearly complete phalanges appear to be manual, so comparisons to extant and other fossil primate species were limited to manual phalanges. Comparisons were made to extant hominoid and cercopithecoid primate genera expressing a variety of positional repertoires and varying degrees of arboreality and terrestriality. The comparisons consisted of a series of bivariate indices derived from previous publications on Miocene catarrhine phalangeal morphology. The proximal phalanges have dorsally expanded proximal articular surfaces, which is characteristic of cercopithecoids and most other Miocene hominoids, and indicates that the predominant positional behaviors involved pronograde quadrupedalism. Among the extant primates, many of the proximal and intermediate phalangeal indices clearly distinguish more habitually terrestrial taxa from those that are predominantly arboreal, and especially from taxa that commonly engage in suspensory activities. For nearly every index, the values of the Pa?alar phalanges occupy an intermediate position-most similar to values for Pan and, to a lesser extent, Macaca-indicating a generalized morphology and probably the use of both arboreal and terrestrial substrates. At least some terrestrial activity is also compatible with reconstructions of the Pa?alar habitat. Most proximal and intermediate phalanges of other middle and late Miocene hominoids have similar index values to those of the Pa?alar specimens, revealing broadly similar manual phalangeal morphology among many Miocene hominoids.     

The Late Permian herbivore Suminia and the early evolution of arboreality in terrestrial vertebrate ecosystems

Vertebrates have repeatedly filled and partitioned the terrestrial ecosystem, and have been able to occupy new, previously unexplored habitats throughout their history on land. The arboreal ecospace is particularly important in vertebrate evolution because it provides new food resources and protection from large ground-dwelling predators. We investigated the skeletal anatomy of the Late Permian (approx. 260 Ma) herbivorous synapsid Suminia getmanovi and performed a morphometric analysis of the phalangeal proportions of a great variety of extant and extinct terrestrial and arboreal tetrapods to discern locomotor function and habitat preference in fossil taxa, with special reference to Suminia. The postcranial anatomy of Suminia provides the earliest skeletal evidence for prehensile abilities and arboreality in vertebrates, as indicated by its elongate limbs, intrinsic phalangeal proportions, a divergent first digit and potentially prehensile tail. The morphometric analysis further suggests a differentiation between grasping and clinging morphotypes among arboreal vertebrates, the former displaying elongated proximal phalanges and the latter showing an elongation of the penultimate phalanges. The fossil assemblage that includes Suminia demonstrates that arboreality and resource partitioning occurred shortly after the initial establishment of the modern type of terrestrial vertebrate ecosystems, with a large number of primary consumers and few top predators.     

On Mesopithecus habitat: Insights from late Miocene fossil vertebrate localities of Bulgaria

The aim of this study is to describe the environments where the cercopithecid Mesopithecus was found during latest Miocene in Europe. For this purpose, we investigate the paleoecology of the herbivorous ungulate mesofauna of three very rich late Miocene fossil localities from southwestern Bulgaria: Hadjidimovo, Kalimantsi and Strumyani. While Mesopithecus has been found in the two first localities, no primate remains have yet been identified in Strumyani. Comparison between localities with and without primates using the herbivore mesofauna allows the cross-corroboration of paleoenvironmental conditions where this primate did and did not live. A multi-parameter statistical approach involving 117 equid and 345 bovid fossil dental and postcranial (phalanges, metapodia, astragali) remains from these three localities provides species to generic-level diet and locomotor habit information in order to characterize the environment in which Mesopithecus evolved. The analysis of dental mesowear indicates that the bovids were mainly mixed feeders, while coeval equids were more engaged in grazing. Meanwhile, postcranial remains show that the ungulate species from Hadjidimovo and Kalimantsi evolved in dry environments with a continuum of habitats ranging from slightly wooded areas to relatively open landscapes, whereas the Mesopithecus-free Strumyani locality was in comparison reflecting a rather contrasted mosaic of environments with predominant open and some more closed and wet areas. Environments in which Mesopithecus is known during the late Miocene were not contrasted landscapes combining open grassy areas and dense forested patches, but instead rather restricted to slightly wooded and homogeneous landscapes including a developed grassy herbaceous layer.     

The Forelimb of Early Miocene Sloths (Mammalia, Xenarthra, Folivora): Morphometrics and Functional Implications for Substrate Preferences

Early Miocene sloths are represented by a diversity of forms ranging from 38 to 95?kg. Their forelimb bones differ in shape from those of their closest living relatives (less than 10?kg), Bradypus and Choloepus. Such differences in shape could be related to differences in substrate preference (arboreal, semiarboreal, or ground-dwelling) or substrate use (climbing, digging, etc.). In order to detect putative patterns related to substrate preference, 21 linear measurements were defined and taken on the forelimb bones. The sample was composed of 22 specimens of fossil sloths and 134 specimens of extant mammals (marsupials, xenarthrans, pangolins, rodents, primates, and carnivorans), including arboreal, semiarboreal, and ground-dwelling taxa. Principal Components Analyses were performed on logarithms of original measurements, while functional indexes (Index of Fossorial Ability, Brachial Index, and Distal Epiphyseal Index) were calculated on raw data. The first three PCs accounted for 93.8% of the cumulative variability. PC1 roughly represented size, while positive values of PC2 represented mechanical advantage for features related to digging habits. Fossil sloths were clearly separated from living ones, sharing a common morphospace with anteaters and other good diggers. Conversely, living sloths shared a morphospace with primates. Similar results were obtained for DEI and IFA, with fossil sloths showing similar values to extant digging mammals. These results suggest that fossil sloths have a different functional pattern of forelimb use than that of extant ones, probably more similar to vermilinguas and pangolins, including putative good digging capabilities and/or semiarboreal habits. Substrate use seems to be interfering in the analysis of substrate preference based on forelimb morphology.     

Herds Overhead: Nimbadon lavarackorum (Diprotodontidae), Heavyweight Marsupial Herbivores in the Miocene Forests of Australia

The marsupial family Diprotodontidae (Diprotodontia, Vombatiformes) is a group of extinct large-bodied (60–2500 kg) wombat-like herbivores that were common and geographically widespread in Cenozoic fossil deposits of Australia and New Guinea. Typically they are regarded to be gregarious, terrestrial quadrupeds and have been likened in body form among placental groups to sheep, rhinoceros and hippopotami. Arguably, one of the best represented species is the zygomaturine diprotodontid Nimbadon lavarackorum which is known from exceptionally well-preserved cranial and postcranial material from the middle Miocene cave deposit AL90, in the Riversleigh World Heritage Area, northwestern Queensland. Here we describe and functionally analyse the appendicular skeleton of Nimbadon lavarackorum and reveal a far more unique lifestyle for this plesiomorphic and smallest of diprotodontids. Striking similarities are evident between the skeleton of Nimbadon and that of the extant arboreal koala Phascolarctos cinereus, including the powerfully built forelimbs, highly mobile shoulder and elbow joints, proportionately large manus and pes (both with a semi-opposable digit I) and exceedingly large, recurved and laterally compressed claws. Combined with the unique (among australidelphians) proportionately shortened hindlimbs of Nimbadon, these features suggest adept climbing ability, probable suspensory behaviour, and an arboreal lifestyle. At approximately 70 kg, Nimbadon is the largest herbivorous mammal to have occupied the forest canopies of Australia - an ecological niche that is no longer occupied in any Australian ecosystem and one that further expands the already significant niche diversity displayed by marsupials during the Cenozoic.     

The fossil record of extant elasmobranchs

Sharks and their relatives (Elasmobranchii) are highly threatened with extinction due to various anthropogenic pressures. The abundant fossil record of fossil taxa has allowed the tracing of the evolutionary history of modern elasmobranchs to at least 250 MYA; nonetheless, exactly how far back the fossil record of living taxa goes has never been collectively surveyed. In this study, the authors assess the representation and extent of the fossil record of elasmobranchs currently living in our oceans by collecting their oldest records and quantifying first appearance dates at different taxonomic levels (i.e., orders, families, genera and species), ecological traits (e.g., body size, habitat and feeding mechanism) and extinction risks (i.e., threatened, not threatened and data deficient). The results of this study confirm the robust representation of higher taxonomic ranks, with all orders, most of the families and over half of the extant genera having a fossil record. Further, they reveal that 10% of the current global species diversity is represented in the geological past. Sharks are better represented and extend deeper in time than rays and skates. While the fossil record of extant genera (e.g., the six gill sharks, Hexanchus) goes as far back as c. 190 MYA, the fossil record of extant species (e.g., the sand shark, Carcharias taurus Rafinesque 1810) extends c. 66 MYA. Although no significant differences were found in the extent of the fossil record between ecological traits, it was found that the currently threatened species have a significantly older fossil record than the not threatened species. This study demonstrate that the fossil record of extant elasmobranchs extends deep into the geologic time, especially in the case of threatened sharks. As such, the elasmobranch geological history has great potential to advance the understanding of how species currently facing extinction have responded to different stressors in the past, thereby providing a deep-time perspective to conservation.     

Biometrical characteristics of primate hands

The lenght proportions of the primate hands and their elements are analyzed in 43 extant genera and 6 fossil genera. The length of the hand in relation to the forelimb length does not characterize taxonomic groups, but rather locomotor modes, such as vertical-clinging-and-leaping, claw-climbing, and terrestrial quadrupedalism, as opposed to arboreal quadrupedalism. The relative lengths of the carpus, metacarpus, and digits appear mainly related to the phylogenetic history of the primates. Paraxony, instead of mesaxony, is the most frequent pattern of the simiiform hand, whereas hypermesaxony characterizes humans, hylobatids, and tarsiers. The proportions of the primitive euprimate hand are discussed in the light of the hand proportions of extant primates. Proportions drawn from hand remains ofMegaladapis edwardsi, Proconsul africanus, Mesopithecus pentelici, Notharctus, Adapis parisiensis, andPlesiadapis insignis are compared to those of extant primates, and discussed from both phylogenetical and functional points of view. To the memory of our colleague Jacques Lessertisseur.     

The parrots (Aves: Psittaciformes) from the Middle Miocene of Sansan (Gers,Southern France)

The occurrence of Archaeopsittacus sp. (Psittaciformes) in the fossil deposits of Sansan (France) is reported, testifying to a survival of this genus in the Middle Miocene, as Archaeopsittacus verreauxi was described from the Early Miocene of Saint-Gérand-le-Puy (France) and was recorded only from its type locality. The data discussed here indicate the presence of two parrot species from Sansan, as it is the type locality of another parrot species, Pararallus dispar, only known from this locality. The differences between the humeri of these two taxa are described in detail, together with the differences from the other European fossil parrot species. The presence of more than one species of parrot in the same locality is not rare, but in Europe it is recorded in Sansan for the second time. Evidence for parrots also confirms the paleoenvironmental reconstruction of Sansan, as parrots are primarily arboreal species. Archaeopsittacus also represents one of the few common elements between the Early and Middle Miocene European bird assemblages.     

Stride lengths and frequencies of arboreal walking in seven species of didelphid marsupials

Didelphid marsupials differ in their use of the forest strata, with corresponding differences in morphology and arboreal walking performances. Similar performances may be reached by different combinations of stride length and frequency, but it has been suggested that arboreal walkers increase velocity by longer strides. Our objective was to determine how stride length and frequency contribute to the velocity in the arboreal walking of seven species of didelphid marsupials of the Atlantic Forest of Brazil. Animals were stimulated to cross five 3-m long horizontal supports of different diameters. The cycle of maximum velocity was chosen to measure relative stride length, frequency, and relative velocity. Except forCaluromys philander, the more arboreal species were faster than the terrestrial species, but maximum velocity of arboreal species was reached by two strategies, increasing stride frequency (Gracilinanus microtarsus, Micoureus demerarae, andDidelphis aurita), or reducing frequency and increasing stride length (Marmosops incanus andC. philander). Increasing velocity in arboreal walking by more frequent strides may reduce oscillations of the body, whereas longer strides may reduce branch swaying. Among the terrestrial species,Philander frenatus performed similarly to more arboreal species, suggesting a potential ability to use the canopy, undetected in field observations.     

Paleobotanical remains from the Paleocene–lower Eocene Vagadkhol Formation, western India and their paleoclimatic and phytogeographic implications

A small assemblage of macro- and micro floral remains comprising fossil leaf impressions, silicified wood, spores, and pollen grains is reported from the Paleocene–lower Eocene Vagadkhol Formation (=Olpad Formation) exposed around Vagadkhol village in the Bharuch District of Gujarat, western India. The fossil leaves are represented by five genera and six species, namely, Polyalthia palaeosimiarum (Annonaceae), Acronychia siwalica (Rutaceae), Terminalia palaeocatapa and T. panandhroensis (Combretaceae), Lagerstroemia patelii (Lythraceae), and a new species, Gardenia vagadkholia (Rubiaceae). The lone fossil wood has been attributed to a new species, Schleicheroxylon bharuchense (Sapindaceae). The palynological assemblage, consisting of pollen grains and spores, comprises eleven taxa with more or less equal representation of pteridophytes, gymnosperms, and angiosperms. Angiospermous pollen grains include a new species Palmidites magnus. Spores are mostly pteridophytic but some fungal spores were also recovered. All the fossil species have been identified in the extant genera. The present day distribution of modern taxa comparable to the fossil assemblage recorded from the Vagadkhol area mostly indicate terrestrial lowland environment. Low frequency of pollen of two highland temperate taxa (Pinaceae) in the assemblage suggests that they may have been transported from a distant source. The wood and leaf taxa in the fossil assemblage are suggestive of tropical moist or wet forest with some deciduousness during the Paleocene–early Eocene. The presence of many fungal taxa further suggests the prevalence of enough humidity at the time of sedimentation.     

A new genus and species of fossil scorpion (?Euscorpiidae) from the Early–Middle Eocene of Pesciara (Bolca,Italy)

Fossil scorpions are among the oldest terrestrial arthropods known from the fossil record. They have a worldwide distribution and a rich fossil record, especially for the Paleozoic. Fossil scorpions from Mesozoic and Cenozoic deposits are usually rare (except in amber-deposits). Here, we describe the only fossil scorpion from the Early to Middle Eocene Pesciara Lagerstätte in Italy. Eoeuscorpius ceratoi gen. et sp. nov. is probably a genus and species within the family Euscorpiidae. This may be the first fossil record of the Euscorpiidae, which are so far only known from four extant genera. Eoeuscorpius ceratoi gen. et sp. nov. was found in the “Lower Part” of the Pesciara Limestone, which is actually dated Late Ypresian stage (between 49.5 and 49.7 Ma). Besides a possible pseudoscorpion, the here-described fossil scorpion is the second arachnid species known from the Bolca Locality.