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Université de Fribourg

New species, revision, and phylogeny of Ronzotherium Aymard, 1854 (Perissodactyla, Rhinocerotidae)

Tissier, Jérémy ; Antoine, Pierre-Olivier ; Becker, Damien

In: European Journal of Taxonomy, 2021, vol. 753, p. 1-80

Ronzotherium is one of the earliest Rhinocerotidae in Europe, which first appeared just after the Eocene/Oligocene transition (Grande Coupure), and became extinct at the end of the Oligocene. It is a large-sized rhinocerotid, with a special position in the phylogeny of this group, as being one of the earliest-branching true Rhinocerotidae. However, its intra-generic systematics has never been...

Université de Fribourg

Phylogeny, taxonomy, and biogeography of Pterocarya (Juglandaceae)

Song, Yi-Gang ; Li, Ying ; Meng, Hong-Hu ; Fragnière, Yann ; Ge, Bin-Jie ; Sakio, Hitoshi ; Yousefzadeh, Hamed ; Bétrisey, Sébastien ; Kozlowski, Gregor

In: Plants, 2020, vol. 9, no. 11, p. 1524

Relict species play an important role in understanding the biogeography of intercontinental disjunctions. Pterocarya (a relict genus) is the valuable model taxon for studying the biogeography of East Asian versus southern European/West Asian disjunct patterns. This disjunction has not been as well studied as others (e.g., between Eastern Asia and North America). Several phylogenetic studies...

Université de Fribourg

Parasite‐driven replacement of a sexual by a closely related asexual taxon in nature

Lohr, Jennifer N. ; Haag, Christoph R.

In: Ecology, 2020, vol. 101, no. 10, p. -

Asexual species are thought to suffer more from coevolving parasites than related sexuals. Yet a variety of studies do not find the patterns predicted by theory. Here, to shine light on this conundrum, we investigate one such case of an asexual advantage in the presence of parasites. We follow the frequency dynamics of sexual and asexual Daphnia pulex in a natural pond that was initially...

Université de Fribourg

New material of Epiaceratherium and a new species of Mesaceratherium clear up the phylogeny of early Rhinocerotidae (Perissodactyla)

Tissier, Jérémy ; Antoine, Pierre-Olivier ; Becker, Damien

In: Royal Society Open Science, 2020, vol. 7, no. 7, p. 200633

Reduction of the anterior dentition (i.e. incisors and canines) is a major adaptative trait of the Rhinocerotidae among Perissodactyla. However, the corresponding evolutionary sequence was lacking a robust phylogenetic frame to support it thus far. Here, we describe a new Oligocene species of Rhinocerotinae, Mesaceratherium sp. nov. from the Swiss locality of Bumbach (MP25 reference level)....

Université de Fribourg

A new alligatoroid from the Eocene of Vietnam highlights an extinct Asian clade independent from extant Alligator sinensis

Massonne, Tobias ; Vasilyan, Davit ; Rabi, Márton ; Böhme, Madelaine

In: PeerJ, 2019, vol. 7, p. e7562

During systematic paleontological surveys in the Na Duong Basin in North Vietnam between 2009 and 2012, well-preserved fossilized cranial and postcranial remains belonging to at least 29 individuals of a middle to late Eocene (late Bartonian to Priabonian age (39–35 Ma)) alligatoroid were collected. Comparative anatomical study of the material warrants the diagnosis of a new taxon,...

Université de Fribourg

Estimating the phylogeny of geoemydid turtles (Cryptodira) from landmark data: an assessment of different methods

Ascarrunz​, Eduardo ; Claude, Julien ; Joyce, Walter G.

In: PeerJ, 2019, vol. 7, p. e7476

Background: In the last 20 years, a general picture of the evolutionary relationships between geoemydid turtles (ca. 70 species distributed over the Northern hemisphere) has emerged from the analysis of molecular data. However, there is a paucity of good traditional morphological characters that correlate with the phylogeny, which are essential for the robust integration of fossil and...

Université de Fribourg

Evolution of gene expression during a transition from environmental to genetic sex determination

Molinier, Cécile ; Reisser, Céline M O ; Fields, Peter D ; Ségard, Adeline ; Galimov, Yan ; Haag, Christoph R

In: Molecular Biology and Evolution, 2019, vol. 36, no. 7, p. 1551–1564

Genetic sex determination (GSD) can evolve from environmental sex determination (ESD) via an intermediate state in which both coexist in the same population. Such mixed populations are found in the crustacean Daphnia magna, where non-male producers (NMP, genetically determined females) coexist with male producers (MP), in which male production is environmentally inducible and can also...