Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

Abstract

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic.

A new protodidelphid (Mammalia, Marsupialia, Didelphimorphia) from the Itaboraí Basin and its implications for the evolution of the Protodidelphidae

“…the pylogenetic analysis support the sister relation between Periprotodidelphis and Anatoliadelphys, recovering a South American ancestral area for the lineage of the last taxon. this result differs from the one of Maga and Beck (2017), who proposed a North American ancestor area for Anatoliadelphys. this result can be considered as preliminary evidence supporting the hypothesis of the Atlantogea, as proposed by Ezcurra and Agnolín (2012).…”

Eocene metatherians from Anatolia illuminate the assembly of an island fauna during Deep Time

“…In contrast to the condition in Anatoliadelphys maasae [ 14 ], the lower molars do not increase markedly in size posteriorly in Orhaniyeia nauta . For example, in Anatoliadelphys maasae the anteroposterior length of M 4 (9.8 mm) is roughly 188% of the anteroposterior length of M 1 (5.2 mm).…”

“…Dental terminology follows the nomenclature of Goin et al [ 21 ]. Additionally, we follow Maga and Beck’s [ 14 ] usage of the term “exodaenodonty” to refer to cheek teeth in which the buccal side of the crown is distended farther basally than the lingual side of the crown.…”

“…Previous research on the middle Eocene Lülük Member of the Uzunçarşıdere Formation in the Orhaniye Basin has highlighted the uniquely endemic character of its mammalian fauna, which dates to ~43 Ma [ 8 , 10 – 15 ]. In addition to the two new metatherians described below, mammalian taxa documented previously from this rock unit include one or more embrithopods [ 11 ], which are extinct large-bodied herbivores that are otherwise known primarily from the Afro-Arabian Plate [ 16 , 17 ], four or five species of the endemic pleuraspidotheriid archaic ungulate Hilalia [ 12 , 13 ], the relatively large-bodied metatherian Anatoliadelphys maasae [ 14 ], the palaeochiropterygid bat Anatolianycteris insularis [ 15 ], and fragmentary fossils of small insectivorous mammals that remain taxonomically enigmatic [ 11 ]. Surprising is the apparent absence of multiple placental mammal clades—including Rodentia, Carnivora, Creodonta, Perissodactyla and Artiodactyla—that are otherwise ubiquitous across Eurasia by the middle Eocene.…”

Correction: Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

“…Maga AM, Beck RMD (2017) Correction: Skeleton of an unusual, cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey. PLoS ONE 12(11): e0188132.…”