Paleoenvironmental inferences on the Late Miocene hominoid-bearing site of Can Llobateres (NE Iberian Peninsula): An ecometric approach based on functional dental traits.

Hispanopithecus laietanus from the Late Miocene (9.8 Ma) of Can Llobateres 1 (CLL1; Vallès-Penedès Basin, NE Iberian Peninsula) represents one of the latest occurrences of fossil apes in Western mainland Europe, where they are last recorded at ∼9.5 Ma. The paleoenvironment of CLL1 is thus relevant for understanding the extinction of European hominoids. To refine paleoenvironmental inferences for CLL1, we apply ecometric models based on functional crown type (FCT) variables-a scoring scheme devised to capture macroscopic functional traits of occlusal shape and wear surfaces of herbivorous large mammal molars. Paleotemperature and paleoprecipitation estimates for CLL1 are provided based on published regional regression models linking average FCT of large herbivorous mammal communities to climatic conditions. A mapping to Whittaker's present-day biome classification is also attempted based on these estimates, as well as a case-based reasoning via canonical variate analysis of FCT variables from five relevant biomes. Estimates of mean annual temperature (25 °C) and mean annual precipitation (881 mm) classify CLL1 as a tropical seasonal forest/savanna, only in partial agreement with the canonical variate analysis results, which classify CLL1 as a tropical rainforest with a higher probability. The former biome agrees better with previous inferences derived from fossil plants and mammals, as well as preliminary isotopic data. The misclassification of CLL1 as a tropical forest is attributed to the mixture of forest-adapted taxa with others adapted to more open environments, given that faunal and plant composition indicates the presence of a dense wetland/riparian forest with more open woodlands nearby. The tested FCT ecometric approaches do not provide unambiguous biome classification for CLL1. Nevertheless, our results are consistent with those from other approaches, thus suggesting that FCT variables are potentially useful to investigate paleoenvironmental changes through time and space-including those that led to the extinction of European Miocene apes.

A revised (earliest Vallesian) age for the hominoid-bearing locality of Can Mata 1 based on new magnetostratigraphic and biostratigraphic data from Abocador de Can Mata (Vallès-Penedès Basin, NE Iberian Peninsula).

The Abocador de Can Mata (ACM) composite stratigraphic sequence (els Hostalets de Pierola, Vallès-Penedès Basin, NE Iberian Peninsula) has yielded a diverse primate assemblage from the late Aragonian (Middle to Late Miocene). Detailed litho-, bio-, and magnetostratigraphic control has enabled an accurate dating of these fossil remains. Comparable data, however, were lacking for the nearby locality of Can Mata 1 (CM1), which yielded a dryopithecine canine of a female individual. Given the lack of hipparionin equids and giraffids, CM1 has been correlated to the latest Aragonian (Mammal Neogene [MN] zone MN7+8). Here we revise the age of CM1 based on fieldwork and associated paleomagnetic samplings undertaken in 2018-2021. Our results extend the ACM composite sequence upward and indicate that CM1 correlates to the earliest Vallesian (MN9). The updated ACM sequence has a thickness of ∼300 m and comprises 12 magnetozones correlated to subchrons C5Ar.1r to C5n.2n (∼12.6-11.1 Ma; latest MN6 to earliest MN9, late Aragonian to earliest Vallesian). CM1 is correlated to C5r.1r (11.146-11.056 Ma), with an interpolated age of 11.11 Ma, thus postdating the dispersal of hipparionin horses into the Vallès-Penedès Basin-which is correlated to the previous subchron C5r.1n, with an interpolated age of 11.18 Ma, and by definition marks the beginning of the Vallesian. CM1 also minimally postdates the earliest record of giraffids at ACM-representing their earliest well-dated occurrence in the basin-being correlated to C5r.1n with an interpolated age of 11.11 Ma. We conclude that CM1 has an earliest Vallesian (MN9) age of ∼11.1 Ma, intermediate between the Aragonian dryopithecins and the Vallesian hispanopithecins. Ongoing paleontological surveillance at ACM thus offers the prospect to yield additional earliest Vallesian ape remains, which are essential to clarify their taxonomic allocation as well as to confirm whether hispanopithecins evolved locally from dryopithecins rather than immigrating from elsewhere during MN9.

Palaeoecological differences underlie rare co-occurrence of Miocene European primates.

BACKGROUND: The two main primate groups recorded throughout the European Miocene, hominoids and pliopithecoids, seldom co-occur. Due to both their rarity and insufficiently understood palaeoecology, it is currently unclear whether the infrequent co-occurrence of these groups is due to sampling bias or reflects different ecological preferences. Here we rely on the densely sampled primate-bearing sequence of Abocador de Can Mata (ACM) in Spain to test whether turnovers in primate assemblages are correlated with palaeoenvironmental changes. We reconstruct dietary evolution through time (ca. 12.6-11.4 Ma), and hence climate and habitat, using tooth-wear patterns and carbon and oxygen isotope compositions of enamel of the ubiquitous musk-deer Micromeryx. RESULTS: Our results reveal that primate species composition is strongly correlated with distinct environmental phases. Large-bodied hominoids (dryopithecines) are recorded in humid, densely-forested environments on the lowermost portion of the ACM sequence. In contrast, pliopithecoids inhabited less humid, patchy ecosystems, being replaced by dryopithecines and the small-bodied Pliobates toward the top of the series in gallery forests embedded in mosaic environments. CONCLUSIONS: These results support the view that pliopithecoid primates preferred less humid habitats than hominoids, and reveal that differences in behavioural ecology were the main factor underpinning their rare co-occurrence during the European Miocene. Our findings further support that ACM hominoids, like Miocene apes as a whole, inhabited more seasonal environments than extant apes. Finally, this study highlights the importance of high-resolution, local investigations to complement larger-scale analyses and illustrates that continuous and densely sampled fossiliferous sequences are essential for deciphering the complex interplay between biotic and abiotic factors that shaped past diversity.

Genetic data from the extinct giant rat from Tenerife (Canary Islands) points to a recent divergence from mainland relatives.

Evolution of vertebrate endemics in oceanic islands follows a predictable pattern, known as the island rule, according to which gigantism arises in originally small-sized species and dwarfism in large ones. Species of extinct insular giant rodents are known from all over the world. In the Canary Islands, two examples of giant rats, †Canariomys bravoi and †Canariomys tamarani, endemic to Tenerife and Gran Canaria, respectively, disappeared soon after human settlement. The highly derived morphological features of these insular endemic rodents hamper the reconstruction of their evolutionary histories. We have retrieved partial nuclear and mitochondrial data from †C. bravoi and used this information to explore its evolutionary affinities. The resulting dated phylogeny confidently places †C. bravoi within the African grass rat clade (Arvicanthis niloticus). The estimated divergence time, 650 000 years ago (95% higher posterior densities: 373 000-944 000), points toward an island colonization during the Günz-Mindel interglacial stage. †Canariomys bravoi ancestors would have reached the island via passive rafting and then underwent a yearly increase of mean body mass calculated between 0.0015 g and 0.0023 g; this corresponds to fast evolutionary rates (in darwins (d), ranging from 7.09 d to 2.78 d) that are well above those observed for non-insular mammals.

Bio- and magnetostratigraphic correlation of the Miocene primate-bearing site of Castell de Barberà to the earliest Vallesian.

Castell de Barberà, located in the Vallès-Penedès Basin (NE Iberian Peninsula), is one of the few European sites where pliopithecoids (Barberapithecus) and hominoids (cf. Dryopithecus) co-occur. The dating of this Miocene site has proven controversial. A latest Aragonian (MN7+8, ca. 11.88-11.18 Ma) age was long accepted by most authors, despite subsequent reports of hipparionin remains that signaled a Vallesian age. On the latter basis, Castell de Barberà was recently correlated to the early Vallesian (MN9, ca. 11.18-10.3 Ma) on tentative grounds. Uncertainties about the provenance of the Hippotherium material and the lack of magnetostratigraphic data precluded more accurate dating. After decades of inactivity, fieldwork was resumed in 2014-2015 at Castell de Barberà, including the original layer (CB-D) that previously delivered most of the fossils. Here we report magnetostratigraphic results for the original outcrop and another nearby section. Our results indicate that CB-D is located in a normal polarity magnetozone in the middle of a short (∼20 m-thick) stratigraphic section. The composite magnetostratigraphic section (∼50 m) has as many as four to six magnetozones. These multiple reversals, coupled with the in situ recovery of a Hippotherium humerus from CB-D in 2015, make it unlikely that any of the sampled normal polarity magnetozones correlate with the long normal polarity subchron C5n.2n (11.056-9.984 Ma), which is characteristic of the early Vallesian. Our results support instead a correlation of CB-D with C5r.1n (11.188-11.146 Ma), where the Aragonian/Vallesian boundary is situated, and therefore indicate an earliest Vallesian age of ∼11.2 Ma for Castell de Barberà. Our results settle the longstanding debate about the Aragonian vs. Vallesian age of this site, which appears roughly coeval with the Creu de Conill 20 locality (11.18 Ma), where hipparionins are first recorded in the Vallès-Penedès Basin.

Can Pallars i Llobateres: A new hominoid-bearing locality from the late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula).

In the Iberian Peninsula, Miocene apes (Hominoidea) are generally rare and mostly restricted to the Vallès-Penedès Basin. Here we report a new hominoid maxillary fragment with M2 from this basin. It was surface-collected in March 2017 from the site of Can Pallars i Llobateres (CPL, Sant Quirze del Vallès), where fossil apes had not been previously recorded. The locality of provenance (CPL-M), which has delivered no further fossil remains, is located very close (ca. 50 m) to previously known CPL outcrops, and not very far (ca. 500 m in NW direction) from the classical hominoid-bearing locality of Can Poncic 1. Here we describe the new fossil and, based on the size and proportions of the M2, justify its taxonomic attribution to Hispanopithecus cf. laietanus, a species previously recorded from several Vallesian sites of the Vallès-Penedès Basin. Based on the associated mammalian fauna from CPL, we also provide a biochronological dating and a paleoenvironmental reconstruction for the site. The associated fauna enables an unambiguous correlation to the Cricetulodon hartenbergeri - Progonomys hispanicus interval local subzone, with an estimated age of 9.98-9.73 Ma (late Vallesian, MN10). Therefore, CPL-M is roughly coeval with the Hispanopithecus laietanus-bearing localities of Can Llobateres 1 and Can Feu 1, and minimally older than those of La Tarumba 1 and Can Llobateres 2. In contrast, CPL-M is younger than the early Vallesian (MN9) localities of Can Poncic 1 (the type locality of Hispanopithecus crusafonti) as well as Polinyà 2 (Gabarró) and Estació Depuradora d'Aigües Residuals-Riu Ripoll 13, where Hispanopithecus sp. is recorded. The associated fauna from CPL indicates a densely forested and humid paleoenvironment with nearby freshwater. This supports the view that Hispanopithecus might have been restricted to dense wetland forests soon before its extinction during the late Vallesian, due to progressive climatic deterioration. Coupled with the existence of other fossiliferous outcrops in the area, this find is most promising for the prospect of discovering additional fossil hominoid remains in the future.

Ten years in the dump: An updated review of the Miocene primate-bearing localities from Abocador de Can Mata (NE Iberian Peninsula).

More than ten years of paleontological fieldwork during the enlargement of the Can Mata Landfill (Abocador de Can Mata [ACM]), in els Hostalets de Pierola (Vallès-Penedès Basin, NE Iberian Peninsula) led to the recovery of >60,000 Miocene vertebrate remains. The huge sampling effort (due to continuous surveillance of heavy machinery digging activity, coupled with manual excavation and screen-washing of sediments) enabled generally rare faunal elements such as pliopithecoid and hominoid primates to be found. Thanks to detailed litho-, bio- and magnetostratigraphic controls, accurate dating is possible for all the recovered primate remains from 19 of the 235 localities defined along the 234 m-thick composite stratigraphic sequence of the ACM. Here we report updated estimated (interpolated) ages for these paleontological localities and review the timing of the primate succession in this area. Our results indicate that the whole ACM sequence is late Aragonian in age (MN6 and MN7+8) and includes seven magnetozones that are correlated to subchrons C5Ar.1r to C5r.2r (ca. 12.6 to 11.4 Ma). Great apes (dryopithecines) are first recorded at 12.4-12.3 Ma, but most of the finds (Anoiapithecus, Pierolapithecus and Dryopithecus) cluster between 12.0 and 11.9 Ma, followed by some indeterminate dryopithecine remains between 11.7 and 11.6 Ma. Pliopithecoids first appear at 12.1 Ma, being subsequently represented by Pliopithecus between 11.9 and 11.7 Ma. The small-bodied hominoid Pliobates is the youngest ACM primate, with an estimated age of 11.6 Ma. Although these primates probably overlapped in time, their co-occurrence is recorded only twice, at 11.9 Ma (a dryopithecine with Pliopithecus) and at 11.6 Ma (a dryopithecine with Pliobates). The rare co-occurrence between great apes and small-bodied catarrhines might be attributable to sampling biases and/or to presumed diverging ecological preferences of these groups. In the future, more detailed analyses of the fauna recovered from the long and densely-sampled ACM sequence will hopefully throw new light on this long-standing, unresolved question.

Updated chronology for the Miocene hominoid radiation in Western Eurasia.

Extant apes (Primates: Hominoidea) are the relics of a group that was much more diverse in the past. They originated in Africa around the Oligocene/Miocene boundary, but by the beginning of the Middle Miocene they expanded their range into Eurasia, where they experienced a far-reaching evolutionary radiation. A Eurasian origin of the great ape and human clade (Hominidae) has been favored by several authors, but the assessment of this hypothesis has been hampered by the lack of accurate datings for many Western Eurasian hominoids. Here we provide an updated chronology that incorporates recently discovered Iberian taxa and further reevaluates the age of many previously known sites on the basis of local biostratigraphic scales and magnetostratigraphic data. Our results show that identifiable Eurasian kenyapithecins (Griphopithecus and Kenyapithecus) are much younger than previously thought (ca. 14 Ma instead of 16 Ma), which casts serious doubts on the attribution of the hominoid tooth from Engelswies (16.3-16.5 Ma) to cf. Griphopithecus. This evidence is further consistent with an alternative scenario, according to which the Eurasian pongines and African hominines might have independently evolved in their respective continents from similar kenyapithecin ancestors, resulting from an early Middle Miocene intercontinental range extension followed by vicariance. This hypothesis, which would imply an independent origin of orthogrady in pongines and hominines, deserves further testing by accurately inferring the phylogenetic position of European dryopithecins, which might be stem pongines rather than stem hominines.

New dental remains of Anoiapithecus and the first appearance datum of hominoids in the Iberian Peninsula.

New dental remains of the fossil great ape Anoiapithecus brevirostris are described from the Middle Miocene local stratigraphic series of Abocador de Can Mata (ACM) in els Hostalets de Pierola (Vallès-Penedès Basin, NE Iberian Peninsula). These specimens correspond to maxillary fragments with upper teeth from two female individuals from two different localities: left P(3)-M(1) (IPS41712) from ACM/C3-Aj (type locality; 11.9 Ma [millions of years ago]); and right M(1)-M(2) and left P(4)-M(2) (IPS35027) from ACM/C1-E* (12.3-12.2 Ma). Relative enamel thickness is also computed in the latter individual and re-evaluated in other Middle Miocene hominoids from ACM, in order to better assess their taxonomic affinities. With regard to maxillary sinus development, occlusal morphology, molar proportions and enamel thickness, the new specimens show greater resemblances with the (male) holotype specimen of A. brevirostris. They differ from Pierolapithecus catalaunicus in displaying less inflated crests, a more lingually-located hypocone, and relatively lower-crowned molars; from Dryopithecus fontani, in the relatively thicker enamel and lower-crowned molars; from Hispanopithecus spp., in the more inflated crown bases, less peripheral cusps and more restricted maxillary sinus; and from Hispanopithecus laietanus also in the thicker crests, more restricted occlusal foveae, and relatively lower-crowned molars. The new specimens of A. brevirostris show some slight differences compared with the holotype of this species: smaller size (presumably due to sexual size dimorphism), and less distally-tapering M(2) occlusal contour (which is highly variable in both extant and extinct hominoids). The reported remains provide valuable new evidence on dental intraspecific variation and sexual dimorphism in Anoiapithecus. From a taxonomic viewpoint, they support the distinction of this taxon from both Dryopithecus and Pierolapithecus. From a chronostratigraphic perspective, IPS35027 from ACM/C1-E* enlarges the known temporal distribution of Anoiapithecus, further representing the oldest record (first appearance datum) of hominoids in the Iberian Peninsula.

The paleoenvironment of Hispanopithecus laietanus as revealed by paleobotanical evidence from the Late Miocene of Can Llobateres 1 (Catalonia, Spain).

The early Vallesian site of Can Llobateres 1 (Vallès-Penedès Basin, Catalonia, Spain) is one of the richest localities of the European Late Miocene, having yielded the most complete remains of the fossil great ape Hispanopithecus laietanus (Primates: Hominidae). Fossil plant remains had been previously reported from this site but mostly remained unpublished. Here we describe an assemblage of plant megaremains recovered in 2010, which provides valuable paleoenvironmental data. This assemblage consists of a mixture of parautochthonous and allochthonous detached organs (leaves, stems, reproductive structures) deposited in marshy areas. The source vegetation mainly consisted of abundant reeds, palms, evergreen laurels and figs that probably grew in or near the marsh boundaries or nearby riparian forests. This environmental picture is consistent with the mammalian fauna, which shows the prevalence of humid forested environments, although somewhat more open woodlands might have been present away from the wet areas. The occurrence of mega-mesothermal taxa, together with the absence of deciduous elements, is consistent with a subtropical to warm-temperate climate. Within this mosaic environment, H. laietanus would have preferred the more humid and forested habitats, which probably were still quite common in the Vallès-Penedès during the early Vallesian. Such habitats would have provided a continuous ripe fruit supply throughout the year to these frugivorous great apes. Paleobotanical data from older sites of the same area and nearby basins show that the zonal vegetation was a warm-temperate mixed forest defined by evergreen laurels, together with leguminous trees and shrubs as well as a significant proportion of deciduous elements. Tropical and subtropical taxa would have been restricted to humid areas in the lowlands. From the late Vallesian onwards, many of these taxa disappeared from the Vallès-Penedès, whereas deciduous trees became dominant in the forested areas and wetlands, thus likely having driven Hispanopithecus to extinction in the study area.

New dental remains of Hispanopithecus laietanus (Primates: Hominidae) from Can Llobateres 1 and the taxonomy of Late Miocene hominoids from the Vallès-Penedès Basin (NE Iberian Peninsula).

Here we report 12 teeth of the fossil great ape Hispanopithecus (Hominidae: Dryopithecinae: Hispanopithecini), recovered in 2011 from the locality of Can Llobateres 1 (MN9, early Vallesian, Late Miocene, ca. 9.7 Ma [millions of years ago]) in the Vallès-Penedès Basin (Catalonia, Spain). Besides an isolated dP(3) from layer CLL1.1b in the eastern (classical) sector of the site, all of the remaining teeth come from facies CLL1.0 (roughly equivalent to CLL1.2 and CLL1.1b), located in the newly excavated western sector, and representing at least two different individuals. Based on facet congruence and degree of wear, all of the upper cheek teeth, a central incisor and a lateral incisor most likely correspond to a single young adult individual of unknown sex, whereas a very worn I(2) and a female C(1) represent one or two additional individual(s). Morphological and metrical comparisons allow us to attribute these remains to Hispanopithecus laietanus, which is the single hominoid species recognized at CLL1. The newly described teeth represent a significant addition to the hypodigm of this taxon, enabling us to more completely assess the degree of variation displayed by several teeth. In light of the new specimens, the previous tooth position assignment of several upper molars from Can Llobateres and Can Poncic is revised, and the criteria employed to distinguish Hispanopithecus crusafonti from H. laietanus are critically evaluated. On the basis of the available upper cheek teeth from these localities, a distinction at the species level between both samples is tentatively favored, mainly on the basis of P(3), M(1) and M(2) proportions as well as I(1) lingual morphology and proportions. The results of the 2011 field season unambiguously confirm that hominoid-bearing fossiliferous layers from CLL1 are not exhausted. Additional excavations at this site are promising for the discovery of additional remains of H. laietanus in the near future.

A unique Middle Miocene European hominoid and the origins of the great ape and human clade.

The great ape and human clade (Primates: Hominidae) currently includes orangutans, gorillas, chimpanzees, bonobos, and humans. When, where, and from which taxon hominids evolved are among the most exciting questions yet to be resolved. Within the Afropithecidae, the Kenyapithecinae (Kenyapithecini + Equatorini) have been proposed as the sister taxon of hominids, but thus far the fragmentary and scarce Middle Miocene fossil record has hampered testing this hypothesis. Here we describe a male partial face with mandible of a previously undescribed fossil hominid, Anoiapithecus brevirostris gen. et sp. nov., from the Middle Miocene (11.9 Ma) of Spain, which enables testing this hypothesis. Morphological and geometric morphometrics analyses of this material show a unique facial pattern for hominoids. This taxon combines autapomorphic features--such as a strongly reduced facial prognathism--with kenyapithecine (more specifically, kenyapithecin) and hominid synapomorphies. This combination supports a sister-group relationship between kenyapithecins (Griphopithecus + Kenyapithecus) and hominids. The presence of both groups in Eurasia during the Middle Miocene and the retention in kenyapithecins of a primitive hominoid postcranial body plan support a Eurasian origin of the Hominidae. Alternatively, the two extant hominid clades (Homininae and Ponginae) might have independently evolved in Africa and Eurasia from an ancestral, Middle Miocene stock, so that the supposed crown-hominid synapomorphies might be homoplastic.

Late Miocene insular mice from the Tusco-Sardinian palaeobioprovince provide new insights on the palaeoecology of the Oreopithecus faunas.

Oreopithecus bambolii is one of the few hominoids that evolved under insular conditions, resulting in the development of unique adaptations that have fueled an intensive debate. The palaeoenvironment associated with this great ape has been the subject of great controversy as well. On the one hand, palaeobotanical data indicate that Oreopithecus likely inhabited mixed mesophytic forests interrupted by swamps; on the other hand, an abundance of hypsodont bovids points towards the existence of dry and open environments. Here, we provide a new approach based on the ecomorphology of the extinct endemic Muridae (rats and mice) of the so-called Oreopithecus faunas. Our results show that the successive species of endemic insular murids (Huerzelerimys and Anthracomys) evolved a number of adaptations observed only in extant family members that include significant proportions of grass in their diet. While this fits the pattern exhibited by large mammals, it contrasts with the available palaeobotanical information, which indicates that grasses were minor components of the vegetation. This contradiction may be explained because these endemic murids may have been adapted to the consumption of particular food items such as hard parts of aquatic plants (as shown by some extant murid species). However, because it is unlikely that the remaining herbivore mammals were adapted to this diet as well, we favour an alternative hypothesis that takes into account the peculiar ecological conditions of insular ecosystems leading to a density-dependent selective regime with strong competition. Such a regime would promote the selection of dental adaptations to increase feeding efficiency and durability of the dentition (such as hypsodonty) as seen in some fossil insular ruminants. This hypothesis requires further testing, but may partly account for parallel evolution of dental traits in phylogenetically unrelated insular mammals.

A new species of Pliopithecus Gervais, 1849 (Primates: Pliopithecidae) from the Middle Miocene (MN8) of Abocador de Can Mata (els Hostalets de Pierola, Catalonia, Spain).

Pliopithecus (Pliopithecus) canmatensis sp. nov. is described from several Late Aragonian localities from Abocador de Can Mata (ACM) in els Hostalets de Pierola (Vallès-Penedès Basin, Catalonia, Spain), spanning from approximately 11.7 to 11.6 Ma (C5r.3r subchron), and being correlated to the MN8 (reference locality La Grive L3). The ACM remains display a pliopithecine dental morphology with well-developed pliopithecine triangles on M/2 and M/3. This, together with other occlusal details, negates an attribution to the subgenus Epipliopithecus. Although slightly smaller, the ACM remains are most similar in size to comparable elements of P. piveteaui and P. antiquus. Several occlusal details (such as the greater development of the buccal cingulid in lower molars) and dental proportions (M/3 much longer than M/2), however, indicate greater similarities with P. antiquus from Sansan and La Grive. The ACM remains, however, differ from P. antiquus in dental proportions as well as occlusal morphology of the lower molars (including the less peripheral position of the protoconid and more medial position of the hypoconulid, the more mesial position of the buccal cuspids as compared to the lingual ones, the narrower but distinct mesial fovea, the higher trigonid, and the more extensive buccal cingulid, among others). These differences justify a taxonomic distinction at the species level of the ACM pliopithecid remains with respect to P. antiquus. Previous pliopithecid findings from the Vallès-Penedès Basin, previously attributed to P. antiquus, are neither attributable to the latter species nor to the newly erected one.

First partial face and upper dentition of the Middle Miocene hominoid Dryopithecus fontani from Abocador de Can Mata (Vallès-Penedès Basin, Catalonia, NE Spain): taxonomic and phylogenetic implications.

A well-preserved 11.8-million-years-old lower face attributed to the seminal taxon Dryopithecus fontani (Primates, Hominidae) from the Catalan site ACM/C3-Ae of the Hostalets de Pierola area (Vallès-Penedès Basin, Catalonia, NE Spain) is described. The new data indicate that D. fontani is distinct at the genus level from Late Miocene European taxa previously attributed to Dryopithecus, which are here reassigned to Hispanopithecus. The new facial specimen also suggests that D. fontani and the Middle Miocene Pierolapithecus catalaunicus are not synonymous. Anatomical and morphometric analyses further indicate that the new specimen shows a combination of lower facial features-hitherto unknown in Miocene hominoids-that resembles the facial pattern of Gorilla, thus providing the first nondental evidence of gorilla-like lower facial morphology in the fossil record. Considering the current evidence, the gorilla-like facial pattern of D. fontani is inferred to be derived relative to previously known stem hominids, and might indicate that this taxon is either an early member of the Homininae or, alternatively, a stem hominid convergent with the lower facial pattern of Gorilla. The biogeographic implications of both alternatives are discussed. This new finding in the Hostalets de Pierola section reinforces the importance of this area for understanding the elusive question of the Middle Miocene origin and early radiation of great apes.

Oldest skeleton of a fossil flying squirrel casts new light on the phylogeny of the group.

Flying squirrels are the only group of gliding mammals with a remarkable diversity and wide geographical range. However, their evolutionary story is not well known. Thus far, identification of extinct flying squirrels has been exclusively based on dental features, which, contrary to certain postcranial characters, are not unique to them. Therefore, fossils attributed to this clade may indeed belong to other squirrel groups. Here we report the oldest fossil skeleton of a flying squirrel (11.6 Ma) that displays the gliding-related diagnostic features shared by extant forms and allows for a recalibration of the divergence time between tree and flying squirrels. Our phylogenetic analyses combining morphological and molecular data generally support older dates than previous molecular estimates (~23 Ma), being congruent with the inclusion of some of the earliest fossils (~36 Ma) into this clade. They also show that flying squirrels experienced little morphological change for almost 12 million years.

Conservatism and adaptability during squirrel radiation: what is mandible shape telling us?

Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing shape and size variation in the mandible of extant squirrels using landmark-based geometric morphometrics in combination with a comparative phylogenetic analysis. Dietary specialization and locomotion were found to be reliable predictors of mandible shape, with the prediction by locomotion probably reflecting the underlying diet. In addition a weak but significant allometric effect could be demonstrated. Our results found a strong phylogenetic signal in the family as a whole as well as in the main clades, which is in agreement with the general notion of squirrels being a conservative group. This fact does not preclude functional explanations for mandible shape, but rather indicates that ancient adaptations kept a prominent role, with most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous adaptations that allow them to specialize on unique dietary resources. Such adaptations mostly occurred in the Callosciurinae and probably reflect their radiation into the numerous ecological niches of the tropical and subtropical forests of Southeastern Asia. Our dietary reconstruction for the oldest known fossil squirrels (Eocene, 36 million years ago) show a specialization on nuts and seeds, implying that the development from protrogomorphous to sciuromorphous skulls was not necessarily related to a change in diet.

A partial skeleton of the fossil great ape Hispanopithecus laietanus from Can Feu and the mosaic evolution of crown-hominoid positional behaviors.

The extinct dryopithecine Hispanopithecus (Primates: Hominidae), from the Late Miocene of Europe, is the oldest fossil great ape displaying an orthograde body plan coupled with unambiguous suspensory adaptations. On the basis of hand morphology, Hispanopithecus laietanus has been considered to primitively retain adaptations to above-branch quadrupedalism-thus displaying a locomotor repertoire unknown among extant or fossil hominoids, which has been considered unlikely by some researchers. Here we describe a partial skeleton of H. laietanus from the Vallesian (MN9) locality of Can Feu 1 (Vallès-Penedès Basin, NE Iberian Peninsula), with an estimated age of 10.0-9.7 Ma. It includes dentognathic and postcranial remains of a single, female adult individual, with an estimated body mass of 22-25 kg. The postcranial remains of the rib cage, shoulder girdle and forelimb show a mixture of monkey-like and modern-hominoid-like features. In turn, the proximal morphology of the ulna-most completely preserved in the Can Feu skeleton than among previously-available remains-indicates the possession of an elbow complex suitable for preserving stability along the full range of flexion/extension and enabling a broad range of pronation/supination. Such features, suitable for suspensory behaviors, are however combined with an olecranon morphology that is functionally related to quadrupedalism. Overall, when all the available postcranial evidence for H. laietanus is considered, it emerges that this taxon displayed a locomotor repertoire currently unknown among other apes (extant or extinct alike), uniquely combining suspensory-related features with primitively-retained adaptations to above-branch palmigrady. Despite phylogenetic uncertainties, Hispanopithecus is invariably considered an extinct member of the great-ape-and-human clade. Therefore, the combination of quadrupedal and suspensory adaptations in this Miocene crown hominoid clearly evidences the mosaic nature of locomotor evolution in the Hominoidea, as well as the impossibility to reconstruct the ancestral locomotor repertoires for crown hominoid subclades on the basis of extant taxa alone.