L'os navicular del primat Anchomomys dona noves pistes sobre la seva locomoció

Un equip de recerca de l'Institut Català de Paleontologia Miquel Crusafont (ICP) ha descrit l'os navicular del petit primat Anchomomys frontanyensis, una espècie trobada a Sant Jaume de Frontanyà (Berguedà, Catalunya) l'any 2011. Les característiques de les seves restes fòssils indiquen que aquesta espècie seria més àgil que d'altres del seu grup, els adapiformes. Els darrers anys, la recerca en aquest jaciment ha permès descriure diverses espècies noves de primats de l'Eocè (fa entre 55 i 33 milions d'anys).Un equipo de investigación del Institut Català de Paleontologia Miquel Crusafont (ICP) ha analizado el hueso navicular del pequeño primate Anchomomys frontanyensis, una especie descrita en sant Jaume de Frontanyà (Berguedà, Catalunya) en el año 2011. Las características de sus restos fósiles indican que esta especie sería más ágil que otras especies de su grupo, los adapiformes. En los últimos años, la investigación en este yacimiento ha permitido describir especies nuevas de primates del Eoceno (hace entre 55 y 33 millones de años).A research team of the Institut Català de Paleontologia Miquel Crusafont (ICP) analyzes the navicular bone of the small primate Anchomomys frontanyensis, a species found in Sant Jaume de Frontanyà (Berguedà, Catalunya). The morphology of these fossil remains suggest that this species was more agile than other members of its group, the adapiforms. In recent years, research on this paleontological site has provided several new species of Eocene (between 55 and 33 million years ago) primates

A new primate assemblage from La Verrerie de Roches (Middle Eocene, Switzerland)

Primates reached a great abundance and diversity during the Eocene, favored by warm temperatures and by the development of dense forests throughout the Northern Hemisphere. Here we describe new primate material from La Verrerie de Roches, a Middle Eocene karstic infill situated in the Jura Region (Switzerland), consisting of more than 80 dental remains. The primate assemblage from La Verrerie de Roches includes five different taxa. The best represented primate is Necrolemur aff. anadoni, similar in size and overall morphology to Necrolemur anadoni but resembling in some features the younger species Necrolemur antiquus. Microchoerines are also represented by two species of Pseudoloris, P. pyrenaicus and Pseudoloris parvulus, constituting the unique joint record of these two species known up to now. Remains of Adapiformes are limited to one isolated tooth of a large anchomomyin and another tooth belonging to the small adapine Microadapis cf. sciureus. The studied primate association allows assigning La Verrerie de Roches to the Robiacian Land Mammal Age. More specifically, this site can be confidently situated between the MP15 and MP16 reference levels, although the primate assemblage probably indicates some degree of temporal mixing. This is the first record of P. pyrenaicus and a form closely related to N. anadoni out of the Iberian Peninsula. The identification of these microchoerines in Switzerland gives further support to the connection of NE Spain and Central Europe during the Middle Eocene

Early euprimates already had a diverse locomotor repertoire: Evidence from ankle bone morphology

Altres ajuts:CLT_2022_EXP_ARQ001SOLC_00000197 financed by the Culture Department of the Generalitat de Catalunya.The morphological adaptations of euprimates have been linked to their origin and early evolution in an arboreal environment. However, the ancestral and early locomotor repertoire of this group remains contentious. Although some tarsal bones like the astragalus and the calcaneus have been thoroughly studied, the navicular remains poorly studied despite its potential implications for foot mobility. Here, we evaluate early euprimate locomotion by assessing the shape of the navicular-an important component of the midtarsal region of the foot-using three-dimensional geometric morphometrics in relation to quantified locomotor repertoire in a wide data set of extant primates. We also reconstruct the locomotor repertoire of representatives of the major early primate lineages with a novel phylogenetically informed discriminant analysis and characterize the changes that occurred in the navicular during the archaic primate-euprimate transition. To do so, we included in our study an extensive sample of naviculars (36 specimens) belonging to different species of adapiforms, omomyiforms, and plesiadapiforms. Our results indicate that navicular shape embeds a strong functional signal, allowing us to infer the type of locomotion of extinct primates. We demonstrate that early euprimates displayed a diverse locomotor behavior, although they did not reach the level of specialization of some living forms. Finally, we show that the navicular bone experienced substantial reorganization throughout the archaic primate-euprimate transition, supporting the major functional role of the tarsus during early primate evolution. This study demonstrates that navicular shape can be used as a reliable proxy for primate locomotor behavior. In addition, it sheds light on the diverse locomotor behavior of early primates as well as on the archaic primate-euprimate transition, which involved profound morphological changes within the tarsus, including the navicular bone

Nous primats de l'Eocè de la Península Ibèrica : implicacions filogenètiques i paleobiogeogràfiques /

Restes de primats de l'Eocè han estat recuperades de diferents jaciments de la Península Ibèrica des de la dècada de 1960, tot i que el seu estudi ha estat escàs des d'aleshores. Aquesta tesi doctoral inclou, d'una banda, una revisió bibliogràfica exhaustiva del registre de primats del Cenozòic de la Península Ibèrica, que representa una actualitació essencial després de les noves troballes fetes durant les últimes dècades i, d'altra banda, la descripció, comparació i determinació taxonòmica de noves restes dentàries de primats (Plesiadapiformes, Adapoïdeus i Omomioïdeus) de diferents jaciments de l'Eocè de la Península Ibèrica: Masia de l'Hereuet i Sossís (Lleida), Sant Jaume de Frontanyà (Barcelona) i Mazaterón (Sòria), emmagatzemades a les col·leccions de l'Institut Català de Paleontologia Miquel Crusafont. Aquests estudis han permès en alguns casos la definició de nous tàxons. Concretament, s'ha descrit l'únic material de plesiadapiforme trobat a Espanya fins ara, procedent del jaciment de Masia de l'Hereuet (Eocè Inferior, Conca Sudpirinenca Central), i s'ha atribuït al gènere Arcius, l'únic gènere de la família Paromomyidae trobat a Europa, encara que l'escassedat de material no ha permès realitzar una determinació a nivell d'espècie. Del jaciment de Sant Jaume de Frontanyà (Eocè Mitjà, Conca Sudpirinenca Oriental) s'han definit dues espècies noves, l'adapoïdeu Anchomomys frontanyensis i l'omomioïdeu Pseudoloris pyrenaicus. La troballa d'A. frontanyensis, que va existir als Pirineus simultàniament amb l'espècie A. gaillardi a França, revela l'existència d'un altre llinatge d'aquest gènere a Europa. La descripció del material de P. pyrenaicus revela que les espècies P. saalae-P. isabenae-P. pyrenaicus-P. parvulus constitueixen un llinatge que va evolucionar durant l'Eocè Mitjà-Superior a Europa. També s'han definit un nou gènere i espècie, l'adapoïdeu Mazateronodon endemicus, i una nova espècie, l'omomioïdeu Pseudoloris cuestai, del jaciment de Mazaterón (Eocè Mitjà, Conca del Duero), que presenten diferències en la dentició amb els representants dels seus respectius grups a les conques pirinenques i a la resta d'Europa. Això reforça el caràcter endèmic de les faunes de la Bioprovíncia Occidental Ibèrica, que havia estat observat prèviament en altres grups de mamífers, causat per l'aïllament d'aquesta regió de la resta d'Europa durant l'Eocè, com a conseqüència de la transgressió marina que connectà els mars Cantàbric i Mediterrani. A més a més, Mazateronodon representa la mostra més rica d'un primat de l'Eocè d'aquesta bioprovíncia. Del jaciment de Sossís (Eocè Superior, Conca Sudpirinenca Central) s'ha descrit un nou gènere i espècie, l'adapoïdeu Nievesia sossissensis, que ha ajudat a aclarir, juntament amb la resta d'adapoïdeus estudiats en aquest treball, tots pertanyents a la tribu Anchomomyini, les relacions filogenètiques entre els anchomomyins i amb la resta d'adapoïdeus i estrepsirins actuals. Els resultats indiquen que els nous gèneres Nievesia i Mazateronodon semblen estar més emparentats entre ells que no pas amb la resta d'anchomomyins, i tot indica que els anchomomyins no estarien més relacionats amb els estrepsirins corona que amb altres adapiformes, i que en canvi hi hauria una relació filogenètica més estreta entre els anchomomyins i els asiadapins i els sivaladàpids que amb altres adapiformes. Tot i això, aquests resultats s'han d'analitzar amb precaució, degut a que és necessària més informació sobre caràcters que ens són encara desconeguts.Fossil remains of Eocene primates have been recovered from many sites in the Iberian Peninsula since the 1960's, although they have been poorly studied. This doctoral thesis includes, on the one hand, a thorough bibliographic revision of all the Cenozoic primate material from the Iberian Peninsula, which represents an essential updating after the new discoveries of the last decades. On the other hand, the description, comparison and taxonomic determination of new primate dental remains of Plesiadapiformes, Adapoidea and Omomyoidea from different Eocene fossil sites of the Iberian Peninsula: Masia de l'Hereuet and Sossís (Lleida), Sant Jaume de Frontanyà (Barcelona) and Mazaterón (Soria), stored in the collections of the Institut Català de Paleontologia Miquel Crusafont. These studies have allowed, in some cases, the definition of new taxa. Specifically, the only material of a plesiadapiform found in Spain has been described, which was recovered from the fossil site of Masia de l'Hereuet (Early Eocene, Southern Pyrenean basins). The studied remains have been attributed to the genus Arcius, the only genus of the family Paromomyidae found in Europe, even though the scarcity of the material has not allowed a specific determination. From the fossil site of Sant Jaume de Frontanyà (Middle Eocene, Southern Pyrenean basins) two new species have been erected, the adapoid Anchomomys frontanyensis and the omomyoid Pseudoloris pyrenaicus. The finding of A. frontanyensis, which existed in the Pyrenees simultaneously with the species A. gaillardi in France, reveals the existence of another lineage of this genus in Europe. The description of the P. pyrenaicus material reveals that the species P. saalae-P. isabenae-P. pyrenaicus-P. parvulus constitute a lineage that evolved during the Middle-Late Eocene in Europe. Moreover, a new genus and species, the adapoid Mazateronodon endemicus, and a new species, the omomyoid Pseudoloris cuestai, have also been described from the locality of Mazaterón (Middle Eocene, Duero Basin). They both present traits in their dentition that differ from the representatives of their groups in the Pyrenean basins and the rest of Europe. This reinforces the endemic character of the faunas of the Western Iberian Bioprovince, which was previously observed in other groups of mammals, caused by the isolation of this region from the rest of Europe during the Eocene, as a consequence to the marine transgression that connected the Cantabric and Mediterranean seas at that time. In addition, Mazateronodon represents the richest sample of an Eocene primate from this bioprovince. From the Sossís fossil site (Late Eocene, Southern Pyrenean basins) a new genus and species has been described, the adapoid Nievesia sossissensis, which will help to clarify, together with the rest of the adapoids studied in this thesis, all belonging to the tribe Anchomomyini, the phylogenetic relationships among the anchomomyins and with the rest of adapoids and extant strepsirhines. The results indicate that the new genera Nievesia and Mazateronodon seem to be more related to each other than to other anchomomyins, and also that the anchomomyins would not be more related to crown strepsirhines than to other adapiforms, and that, on the contrary, there would be a closer phylogenetic relationship between anchomomyins, asiadapines and sivaladapids than to other adapiforms. Nevertheless, these results need to be taken with caution, since more information about still unknown characters is needed

Agerinia marandati sp. nov., a new early Eocene primate from the Iberian Peninsula, sheds new light on the evolution of the genus Agerinia

Background. The Eocene was the warmest epoch of the Cenozoic and recorded the appearance of several orders of modern mammals, including the first occurrence of Euprimates. During the Eocene, Euprimates were mainly represented by two groups, adapiforms and omomyiforms, which reached great abundance and diversity in the Northern Hemisphere. Despite this relative abundance, the record of early Eocene primates from the European continent is still scarce and poorly known, preventing the observation of clear morphological trends in the evolution of the group and the establishment of phylogenetic relationships among different lineages. However, knowledge about the early Eocene primates from the Iberian Peninsula has been recently increased through the description of new material of the genus Agerinia from several fossil sites from Northeastern Spain. - Methods. Here we present the first detailed study of the euprimate material from the locality of Masia de l'Hereuet (early Eocene, NE Spain). The described remains consist of one fragment of mandible and 15 isolated teeth. This work provides detailed descriptions, accurate measurements, high-resolution figures and thorough comparisons with other species of Agerinia as well with other Eurasian notharctids. Furthermore, the position of the different species of Agerinia has been tested with two phylogenetic analyses. - Results. The new material from Masia de l'Hereuet shows several traits that were previously unknown for the genus Agerinia, such as the morphology of the upper and lower fourth deciduous premolars and the P2, and the unfused mandible. Moreover, this material clearly differs from the other described species of Agerinia, A. roselli and A. smithorum, thus allowing the erection of the new species Agerinia marandati. The phylogenetic analyses place the three species of Agerinia in a single clade, in which A. smithorum is the most primitive species of this genus. - Discussion. The morphology of the upper molars reinforces the distinction of Agerinia from other notharctids like Periconodon. The analysis of the three described species of the genus, A. smithorum, A. marandati and A. roselli, reveals a progressive change in several morphological traits such as the number of roots and the position of the P1 and P2, the molarization of the P4, the reduction of the paraconid on the lower molars and the displacement of the mental foramina. These gradual modifications allow for the interpretation that these three species, described from the early Eocene of the Iberian Peninsula, are part of a single evolutionary lineage. The stratigraphical position of Masia de l'Hereuet and Casa Retjo-1 (type locality of A. smithorum) and the phylogenetic analyses developed in this work support this hypothesis

Systematic and locomotor diversification of the Adapis group (Primates, Adapiformes) in the late Eocene of the Quercy (Southwest France), revealed by humeral remains

Altres ajuts: Beatriu de Pinós (2017 BP 00003)Twenty humeral specimens from the old and new Quercy collections attributed to the fossil primates Adapis and Palaeolemur are described and analysed together. We provide a qualitative and quantitative analysis of the different humeri, revealing that high variability is present within the "Adapis group" sample. Six different morphotypes are identified, confirming that what has often been called "Adapis parisiensis" is a mix of different species that present different locomotor adaptations. Such a relatively high level of locomotor diversity is unique in the Paleogene primate fossil record. The humeral proportions of Adapis overlap with different groups of extant strepsirrhines and platyrrhines depending on the specimen, so the popular view of Adapis as a loris-like slow climbing primate does not apply to the whole sample presented here. Moreover, different humeral features traditionally associated with "Adapis parisiensis" such as the absence of a zona conoidea and a reduced brachioradialis flange, are variable depending on the sample studied. In addition, results of our analyses show that adapine and omomyid humeral morphology overlap extensively, leading us to question the accuracy of taxonomic attributions based on morphology of isolated humeri at localities where omomyids and adapines of similar size coexist. Finally, assuming our different morphotypes represent different species within two genera, we propose a phylogenetic hypothesis relating these morphotypes, which inhabited a small geographic area

New dental material and redescription of Agerinia roselli (Primates, Adapiformes) from Les Saleres (early Eocene, NE Iberian Peninsula)

In this work, new dental material of Agerinia roselli from its type locality, Les Saleres (NE Spain), is described. An emended diagnosis of the species is provided, together with a redescription of the entire hypodigm from that locality, which was necessary due to some inaccuracies in previous descriptions. The studied material includes 12 teeth (from P3 to M3); the roots of the anterior premolars preserved in a mandible fragment are reported for the first time. Some previously undescribed traits have been identified after the new analysis of this material, such as the P4 with distinct hypoconid and entoconid and the tiny paraconid on the M1. A detailed comparison with other cercamoniines has been made. The body mass of A. roselli, ranging from 650 to 900 g, has also been estimated. The presence of a minuscule paraconid in the M1 is the most reliable criterion for distinguishing this molar from the M2. This is supported by the complete absence of paraconid in four M2 preserved in mandible fragments. The trigonid length seems to be less reliable for distinguishing M1 from M2, due to its high variability in this species. Concluding, this study updates the knowledge about the dental anatomy of A. roselli and demonstrates that it is a valid taxon clearly distinguishable from other cercamoniines

Nous primats de l'Eocè de la Península Ibèrica: implicacions filogenètiques i paleobiogeogràfiques

Restes de primats de l’Eocè han estat recuperades de diferents jaciments de la Península Ibèrica des de la dècada de 1960, tot i que el seu estudi ha estat escàs des d’aleshores. Aquesta tesi doctoral inclou, d’una banda, una revisió bibliogràfica exhaustiva del registre de primats del Cenozòic de la Península Ibèrica, que representa una actualitació essencial després de les noves troballes fetes durant les últimes dècades i, d’altra banda, la descripció, comparació i determinació taxonòmica de noves restes dentàries de primats (Plesiadapiformes, Adapoïdeus i Omomioïdeus) de diferents jaciments de l’Eocè de la Península Ibèrica: Masia de l’Hereuet i Sossís (Lleida), Sant Jaume de Frontanyà (Barcelona) i Mazaterón (Sòria), emmagatzemades a les col·leccions de l’Institut Català de Paleontologia Miquel Crusafont. Aquests estudis han permès en alguns casos la definició de nous tàxons. Concretament, s’ha descrit l’únic material de plesiadapiforme trobat a Espanya fins ara, procedent del jaciment de Masia de l’Hereuet (Eocè Inferior, Conca Sudpirinenca Central), i s’ha atribuït al gènere Arcius, l’únic gènere de la família Paromomyidae trobat a Europa, encara que l’escassedat de material no ha permès realitzar una determinació a nivell d’espècie. Del jaciment de Sant Jaume de Frontanyà (Eocè Mitjà, Conca Sudpirinenca Oriental) s’han definit dues espècies noves, l’adapoïdeu Anchomomys frontanyensis i l’omomioïdeu Pseudoloris pyrenaicus. La troballa d’A. frontanyensis, que va existir als Pirineus simultàniament amb l’espècie A. gaillardi a França, revela l’existència d’un altre llinatge d’aquest gènere a Europa. La descripció del material de P. pyrenaicus revela que les espècies P. saalae-P. isabenae-P. pyrenaicus-P. parvulus constitueixen un llinatge que va evolucionar durant l’Eocè Mitjà-Superior a Europa. També s’han definit un nou gènere i espècie, l’adapoïdeu Mazateronodon endemicus, i una nova espècie, l’omomioïdeu Pseudoloris cuestai, del jaciment de Mazaterón (Eocè Mitjà, Conca del Duero), que presenten diferències en la dentició amb els representants dels seus respectius grups a les conques pirinenques i a la resta d’Europa. Això reforça el caràcter endèmic de les faunes de la Bioprovíncia Occidental Ibèrica, que havia estat observat prèviament en altres grups de mamífers, causat per l’aïllament d’aquesta regió de la resta d’Europa durant l’Eocè, com a conseqüència de la transgressió marina que connectà els mars Cantàbric i Mediterrani. A més a més, Mazateronodon representa la mostra més rica d’un primat de l’Eocè d’aquesta bioprovíncia. Del jaciment de Sossís (Eocè Superior, Conca Sudpirinenca Central) s’ha descrit un nou gènere i espècie, l’adapoïdeu Nievesia sossissensis, que ha ajudat a aclarir, juntament amb la resta d’adapoïdeus estudiats en aquest treball, tots pertanyents a la tribu Anchomomyini, les relacions filogenètiques entre els anchomomyins i amb la resta d’adapoïdeus i estrepsirins actuals. Els resultats indiquen que els nous gèneres Nievesia i Mazateronodon semblen estar més emparentats entre ells que no pas amb la resta d’anchomomyins, i tot indica que els anchomomyins no estarien més relacionats amb els estrepsirins corona que amb altres adapiformes, i que en canvi hi hauria una relació filogenètica més estreta entre els anchomomyins i els asiadapins i els sivaladàpids que amb altres adapiformes. Tot i això, aquests resultats s’han d’analitzar amb precaució, degut a que és necessària més informació sobre caràcters que ens són encara desconeguts.Fossil remains of Eocene primates have been recovered from many sites in the Iberian Peninsula since the 1960’s, although they have been poorly studied. This doctoral thesis includes, on the one hand, a thorough bibliographic revision of all the Cenozoic primate material from the Iberian Peninsula, which represents an essential updating after the new discoveries of the last decades. On the other hand, the description, comparison and taxonomic determination of new primate dental remains of Plesiadapiformes, Adapoidea and Omomyoidea from different Eocene fossil sites of the Iberian Peninsula: Masia de l’Hereuet and Sossís (Lleida), Sant Jaume de Frontanyà (Barcelona) and Mazaterón (Soria), stored in the collections of the Institut Català de Paleontologia Miquel Crusafont. These studies have allowed, in some cases, the definition of new taxa. Specifically, the only material of a plesiadapiform found in Spain has been described, which was recovered from the fossil site of Masia de l’Hereuet (Early Eocene, Southern Pyrenean basins). The studied remains have been attributed to the genus Arcius, the only genus of the family Paromomyidae found in Europe, even though the scarcity of the material has not allowed a specific determination. From the fossil site of Sant Jaume de Frontanyà (Middle Eocene, Southern Pyrenean basins) two new species have been erected, the adapoid Anchomomys frontanyensis and the omomyoid Pseudoloris pyrenaicus. The finding of A. frontanyensis, which existed in the Pyrenees simultaneously with the species A. gaillardi in France, reveals the existence of another lineage of this genus in Europe. The description of the P. pyrenaicus material reveals that the species P. saalae-P. isabenae-P. pyrenaicus-P. parvulus constitute a lineage that evolved during the Middle-Late Eocene in Europe. Moreover, a new genus and species, the adapoid Mazateronodon endemicus, and a new species, the omomyoid Pseudoloris cuestai, have also been described from the locality of Mazaterón (Middle Eocene, Duero Basin). They both present traits in their dentition that differ from the representatives of their groups in the Pyrenean basins and the rest of Europe. This reinforces the endemic character of the faunas of the Western Iberian Bioprovince, which was previously observed in other groups of mammals, caused by the isolation of this region from the rest of Europe during the Eocene, as a consequence to the marine transgression that connected the Cantabric and Mediterranean seas at that time. In addition, Mazateronodon represents the richest sample of an Eocene primate from this bioprovince. From the Sossís fossil site (Late Eocene, Southern Pyrenean basins) a new genus and species has been described, the adapoid Nievesia sossissensis, which will help to clarify, together with the rest of the adapoids studied in this thesis, all belonging to the tribe Anchomomyini, the phylogenetic relationships among the anchomomyins and with the rest of adapoids and extant strepsirhines. The results indicate that the new genera Nievesia and Mazateronodon seem to be more related to each other than to other anchomomyins, and also that the anchomomyins would not be more related to crown strepsirhines than to other adapiforms, and that, on the contrary, there would be a closer phylogenetic relationship between anchomomyins, asiadapines and sivaladapids than to other adapiforms. Nevertheless, these results need to be taken with caution, since more information about still unknown characters is needed

Un os del tars revela noves pistes sobre la locomoció dels primers primats

Investigadors de l'Institut Català de Paleontologia, la UAB, el Naturhistorisches Museum Bern y la Université de Lyon han dut a terme un estudi paleobiològic sobre la diversitat locomotora dels primers euprimats. Aquest treball, que ha utilitzat com a objecte d'anàlisi l'os navicular, situat en la regió del tars, en el peu, proposa que els primers euprimats ja mostraven un ampli rang de repertoris locomotors, permetent-los explotar nínxols diferents del medi arbori.Investigadores del Institut Català de Paleontologia, la UAB, el Naturhistorisches Museum Bern i la Université de Lyon ha realizado un estudio paleobiológico sobre la diversidad locomotora de los primeros euprimates. Este trabajo, que ha utilizado como objeto de análisis el hueso navicular, situado en la región del tarso, en el pie, propone que los primeros euprimates ya mostraban un amplio rango de repertorios locomotores, permitiéndoles explotar nichos diferentes del medio arbóreo.Researchers of the Institut Català de Paleontologia, the UAB, the Naturhistorisches Museum Bern and the Université de Lyon has conducted a paleobiological study on the locomotor diversity of the first euprimates. This work, that has analysed the navicular bone, located in the tarsal region, in the foot, proposes that the first euprimates already displayed a wide range of locomotor repertoires, allowing them to exploit different niches in the arboreal milieu

Systematic and locomotor diversification of the Adapis group (Primates, Adapiformes) in the late Eocene of the Quercy (Southwest France), revealed by humeral remains

Altres ajuts: Beatriu de Pinós (2017 BP 00003)Twenty humeral specimens from the old and new Quercy collections attributed to the fossil primates Adapis and Palaeolemur are described and analysed together. We provide a qualitative and quantitative analysis of the different humeri, revealing that high variability is present within the "Adapis group" sample. Six different morphotypes are identified, confirming that what has often been called "Adapis parisiensis" is a mix of different species that present different locomotor adaptations. Such a relatively high level of locomotor diversity is unique in the Paleogene primate fossil record. The humeral proportions of Adapis overlap with different groups of extant strepsirrhines and platyrrhines depending on the specimen, so the popular view of Adapis as a loris-like slow climbing primate does not apply to the whole sample presented here. Moreover, different humeral features traditionally associated with "Adapis parisiensis" such as the absence of a zona conoidea and a reduced brachioradialis flange, are variable depending on the sample studied. In addition, results of our analyses show that adapine and omomyid humeral morphology overlap extensively, leading us to question the accuracy of taxonomic attributions based on morphology of isolated humeri at localities where omomyids and adapines of similar size coexist. Finally, assuming our different morphotypes represent different species within two genera, we propose a phylogenetic hypothesis relating these morphotypes, which inhabited a small geographic area