Raül Carmona

Kretzoiarctos gen. nov., the Oldest Member of the Giant Panda Clade

The phylogenetic position of the giant panda, Ailuropoda melanoleuca (Carnivora: Ursidae: Ailuropodinae), has been one of the most hotly debated topics by mammalian biologists and paleontologists during the last century. Based on molecular data, it is currently recognized as a true ursid, sister-taxon of the remaining extant bears, from which it would have diverged by the Early Miocene. However, from a paleobiogeographic and chronological perspective, the origin of the giant panda lineage has remained elusive due to the scarcity of the available Miocene fossil record. Until recently, the genus Ailurarctos from the Late Miocene of China (ca. 8–7 mya) was recognized as the oldest undoubted member of the Ailuropodinae, suggesting that the panda lineage might have originated from an Ursavus ancestor. The role of the purported ailuropodine Agriarctos, from the Miocene of Europe, in the origins of this clade has been generally dismissed due to the paucity of the available material. Here, we describe a new ailuropodine genus, Kretzoiarctos gen. nov., based on remains from two Middle Miocene (ca. 12–11 Ma) Spanish localities. A cladistic analysis of fossil and extant members of the Ursoidea confirms the inclusion of the new genus into the Ailuropodinae. Moreover, Kretzoiarctos precedes in time the previously-known, Late Miocene members of the giant panda clade from Eurasia (Agriarctos and Ailurarctos). The former can be therefore considered the oldest recorded member of the giant panda lineage, which has significant implications for understanding the origins of this clade from a paleobiogeographic viewpoint.

First cranial remains of Cheirogaster richardi (Testudines: Testudinidae) from the Late Miocene of Ecoparc de Can Mata (Vallès-Penedès Basin, NE Iberian Peninsula): taxonomic and phylogenetic implications

Although skulls of extinct Testudinidae are generally much scarcer than shell remains, when available they provide important data for resolving taxonomic and phylogenetic problems, as illustrated here by two well-preserved giant tortoise skulls from the early Vallesian (MN9, Late Miocene) of Ecoparc de Can Mata (ECM; els Hostalets de Pierola, Vallès-Penedès Basin, NE Iberian Peninsula). These specimens, referable to the extinct genus Cheirogaster, differ significantly from C. bolivari and are assigned to C. richardi, whose cranial morphology was previously unknown. This nominal taxon had been considered a junior subjective synonym of C. bolivari, due to a previous neotype designation for the former, based on shell remains, that did not meet the requirements of the International Code of Zoological Nomenclature. This designation is here considered invalid because it was based on material from a different geographical area, even though remains from the original type locality area were available. Given that the holotype of C. richardi (from the early Vallesian of els Hostalets de Pierola) has been destroyed, to clarify the taxonomic status of this taxon we here designate one of the two ECM skulls as the neotype of the species. On this basis, an emended diagnosis is provided, which leads us to conclude that two different species are recorded from the Iberian Miocene: C. bolivari, from the middle Aragonian of the inner Iberian basins; and C. richardi, from the latest Aragonian and Vallesian of the Vallès-Penedès Basin. Additional cranial material of Cheirogaster from inner Iberia would be required to clarify whether these species display distinct geographical distributions and/or different chronostratigraphical ranges. A cladistic analysis of Testudinidae based on cranial morphology supports a sister-taxon relationship between Cheirogaster and Centrochelys. Overall, our results highlight the significance of cranial morphology for attaining a better understanding of turtle taxonomy and phylogenetic relationships.

Revision of the extinct Pleistocene tortoise Testudo lunellensis Almera and Bofill, 1903 from Cova de Gràcia (Barcelona, Spain)

Testudo lunellensis Almera and Bofill, 1903 from the Middle Pleistocene of Cova de Gracia (Park Guell, Barcelona, Spain) is a valid species belonging to the clade of the extant Testudo hermanni – a diagnostic feature being the narrowed vertebral scutes. Thanks to still unpublished material, T. lunellensis is diagnosed for the first time and its shell morphology described in detail. This species is uniquely characterized, among others, by tall peripheral bones and by a peculiar shape of the anterior lobe of the plastron, somewhat recalling the species referred to Testudo s.s. (the clade containing the extant species Testudo graeca, Testudo kleinmanni and Testudo marginata). Given that the purported valid species from Lunel-Viel (Middle Pleistocene, France) is still unnamed and undescribed, T. lunellensis from Cova de Gracia is currently the stratigraphically youngest extinct Testudo species. The co-occurrence in T. lunellensis of characters typical of both T. hermanni and Testudo s.s. further testifies the phenotypic plasticity of tortoises and the mosaic distribution of morphological characters, which hinders a clear-cut assessment of the relationships of extant tortoises when based exclusively on morphology. Further analyses of the phylogeny of Testudo should consider fossil and extant taxa together, as well as both morphological and genetic characters.

New craniodental remains of the barbourofelid Albanosmilus jourdani (Filhol, 1883) from the Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula) and the phylogeny of the Barbourofelini

Available remains of the barbourofelin Albanosmilus jourdani from the Middle to Late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula) are described. In addition to the dentognathic remains described by previous authors, the new material includes a complete cranium, a calvarium and several mandibles from Abocador de Can Mata, Creu Conill 20 and Hostalets Superior. It is concluded that Albanosmilus, previously considered a subjective junior synonym of Sansanosmilus, must be resurrected as a polytypic genus including A. jourdani (= A. vallesiensis). The most plesiomorphic North American barbourofelin, previously included in Barbourofelis, is also transferred into Albanosmilus as A. whitfordi. An emended diagnosis of Albanosmilus is provided. The results of a cladistic analysis support the monophyly of the family Barbourofelidae and the tribe Barbourofelini, further indicating that amongst the latter, Sansanosmilus occupies the basalmost position. The two Albanosmilus species are more derived, although the analysis fails to resolve conclusively whether A. whitfordi is more closely related to A. jourdani or Barbourofelis s.s. From a palaeobiogeographical viewpoint, our results suggest that: (1) barbourofelins originated in Eurasia during the early Middle Miocene; (2) Barbourofelis originated in North America during the late Middle Miocene, following the dispersal of Eurasian Albanosmilus into that continent; and (3) the presence of Barbourofelis in Turkey during the Late Miocene may represent a later independent dispersal event from North America back into Eurasia.

New Craniodental Remains of Trocharion albanense Major, 1903 (Carnivora, Mustelidae), from the Vallès-Penedès Basin (Middle to Late Miocene, Barcelona, Spain)

ABSTRACT Cranial and dentognathic remains of Trocharion albanense (Carnivora, Mustelidae, Leptarctinae) from the Vallès-Penedès Basin (Barcelona, Spain), ranging from the middle to the late Miocene, are described. Most of the newly described material comes from several sites of the Abocador de Can Mata (ACM) section (in the municipal term of els Hostalets de Pierola), but remains from other Catalan localities (Sant Quirze, Castell de Barberà, and Can Llobateres) are also described. The material from ACM includes two partial crania and several mandibles. This enables description of several aspects of craniodental morphology previously unknown for this taxon, such as the presence of first upper premolars, as well as the presence of a conspicuous and rhomboid double temporal crest. Accordingly, an emended diagnosis of the genus Trocharion is provided, together with a differential diagnosis with respect to other leptarctine genera. A cladistic analysis based on craniodental features is consistent with Trocharion being the basalmost member of the Leptarctinae, and suggests that the carnassial notch (still present in this taxon) was independently lost in leptarctines and in other mustelids.