New material of Pseudoloris parvulus (Microchoerinae, Omomyidae, Primates) from the Late Eocene of Sossís (northeastern Spain) and its implications for the evolution of Pseudoloris

Abstract

The species Pseudoloris parvulus, identified in several Middle and Late Eocene European sites, was previously known in the Iberian Peninsula by a single mandible preserving P4-M3 from Sossís (Southern Pyrenean Basins, northeastern Spain), described in the 1960s. Further field work at this Late Eocene site has led to the recovery of a large number of mammal remains, including the additional material of P. parvulus described in this paper. Some specimens of P. parvulus from this locality have also been recently found in the collections of the Naturhistorisches Museum Basel, Switzerland. The whole sample consists of 11 mandible fragments including several teeth, three upper dental series and nearly 80 isolated teeth including all of the dental elements, and represents the most complete sample of the genus described from the Iberian Peninsula. This abundant material allows us to provide an emended diagnosis for the species and to observe several directional changes in the dental morphology of the lineage including the species Pseudoloris saalae, Pseudoloris isabenae, Pseudoloris pyrenaicus and P. parvulus. These directional changes include the progressive reduction of the paraconid in the lower molars and the increase in size of the hypocone, metaconule and paraconule in the upper molars. Moreover, despite the overall resemblance among all of the samples ascribed to P. parvulus, we also recognize some differences, particularly an increase in size and better development of the hypocone from the oldest populations of the species, such as Le Bretou, to the most recent ones, like Sossís and Perrière. Therefore, this study sheds new light on the evolution of this genus, which inhabited Europe from the Middle Eocene to the Early Oligocene.

Agerinia smithorum sp. nov., a new early Eocene primate from the Iberian Peninsula

“…Similar trends in some of these traits have been observed in other early primate lineages. The reduction of the paraconid in the lower molars is a general trend in the evolution of the different primate lineages (Ankel‐Simons, ; Godinot, ); particularly the paraconid decreases with time, changing from a distinct cuspid to a crest or even becoming completely absent in some genera like Pseudoloris and Necrolemur (Minwer‐Barakat et al, ).…”

“…The study of Eocene primates in the Iberian Peninsula started with the works of Crusafont‐Pairó, who discovered several primate‐bearing fossil sites in the Ebro and Pyrenean basins, and described a number of taxa, including the early Eocene species Agerinia roselli (Crusafont‐Pairó, ). This research line has been resumed in the last decade by the team of the Institut Català de Paleontologia Miquel Crusafont (ICP); however, recent studies developed in this institution are focused on middle Eocene (Marigó Minwer‐Barakat, & Moyà‐Solà, ; Marigó, Roig, Seiffert, Moyà‐Solà, & Boyer, ; Minwer‐Barakat, Marigó, & Moyà‐Solà, ) and late Eocene primates (Marigó, Minwer‐Barakat, & Moyà‐Solà, ; Minwer‐Barakat, Marigó, & Moyà‐Solà, ; Minwer‐Barakat, Badiola, Marigó, & Moyà‐Solà, ; Minwer‐Barakat, Marigó, Femenias‐Gual, & Moyà‐Solà, ). On the contrary, and despite the interest of the early steps of the evolution of the primate clade in Europe, only few and preliminary studies have dealt with the early Eocene primates from the Iberian Peninsula (Femenias‐Gual, Marigó, Minwer‐Barakat, & Moyà‐Solà, , ; Marigó et al, ).…”

Necrolemur anadoni, a new species of Microchoerinae (Omomyidae, Primates) from the Middle Eocene of Sant Jaume de Frontanyà (Pyrenees, Northeastern Spain)

“…The studied material is housed in the collections of the Institut Català de Paleontologia Miquel Crusafont (Sabadell, Barcelona, Spain). The nomenclature used in the descriptions of the teeth is that described in Minwer‐Barakat et al (). Following Hooker and Harrison (), the terms “anterior” and “posterior” are used specifically for the descriptions of the incisors because, whereas the posterior direction equates to distal, anterior does not equate with mesial.…”

“…Knowledge about microchoerines considerably increased in recent years due to the description of new taxa (Hooker, ; Hooker and Harrison, ). In the Iberian Peninsula, late studies about this group were focused on the description of new material of the genera Pseudoloris (Minwer‐Barakat et al, ) and Microchoerus (Minwer‐Barakat et al, ).…”

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

“…On the contrary, A. roselli only displays a tiny paraconid on the M 1 , in which the trigonid basin is closed. It is widely known that the lower molar paraconid tends to be reduced during the evolution of different primate lineages (Ankel-Simons, 2007; Godinot, 2015); for example in the genera Pseudoloris and Necrolemur the size of the paraconid decreases with time, changing from a distinct cuspid to a crest or even becoming completely absent (Minwer-Barakat, Marigó & Moyà-Solà, 2010; Minwer-Barakat, Marigó & Moyà-Solà, 2015; Minwer-Barakat et al, 2015). The same trend can be identified in the species A. smithorum, A. marandati and A. roselli (Fig.…”