New findings of Prototherium ausetanum (Mammalia, Pan-Sirenia) from paving stones in Girona (Catalonia, Spain)?

Taxonomic and morphological approaches on Eocene sirenians from Catalonia (Spain) benefit from a newly discovered specimen found in a quite unusual locality, the pedestrian zone in the city of Girona. Two fossil-bearing limestone slabs from middle Eocene (Bartonian) layers of a quarry in the wider surrounding area north-west of Barcelona, were CT-scanned in the Clínica Girona to enhance more detailed investigations. Post-processing of the scans and, as far as possible, 3D-reconstruction of the preserved elements in the slabs was performed at Museum für Naturkunde Berlin. Thereby, a skull of a Dugong specimen was used as a reference point. Based on the combined analysis of macroscopic and CT-data, the specimen most likely represents Prototherium ausetanum Balaguer & Alba, 2016 and complements the available information of the holotype and hitherto only known specimen of that species. The Girona specimen is an adult, but small individual that corroborates P. ausetanum as a generally small-sized species compared to other known Prototherium taxa

Morphological and systematic re-assessment of the late Oligocene “Halitherium” bellunense reveals a new crown group genus of Sirenia

“Halitherium” bellunense is exclusively known from a single individual from upper Oligocene glauconitic sandstone near Belluno, northern Italy. According to a review of its morphological basis, which consists of associated cranial elements, some vertebrae and ribs, this specimen is identified as a juvenile, because the first upper incisor (I1) and supposedly second upper molar (M2) are not fully erupted. However, its juvenile status allowed only cautious conclusions on its taxonomy and systematic affinity. The presence of a nasal process of the premaxilla with a broadened and bulbous posterior end, and a lens-shaped I1, corroborate an evolutionarily-derived status of this species that places it well within the sirenian crown group Dugonginae. Considering these new data and in order to avoid continued misuse of the inappropriate generic name of Halitherium, a new generic name, Italosiren gen. nov., and emended species diagnosis are supplied for this taxon

Re-evaluation of the taxonomic and systematic status of “Halitherium” antillense Matthew, 1916 (Mammalia, Sirenia)

<jats:title>Abstract</jats:title><jats:p><jats:italic>Halitherium antillense</jats:italic> Matthew, 1916 was established on a left mandibular fragment and two vertebrae from late Oligocene deposits of Puerto Rico. This species was only provisionally referred to the genus <jats:italic>Halitherium</jats:italic> and its taxonomic status and systematic affinities remained doubtful. In the course of the revision of the <jats:italic>Halitherium</jats:italic>-species complex and the meanwhile invalid generic name “<jats:italic>Halitherium</jats:italic>”, the holotype, and only known specimen, is re-investigated. A number of morphological characters usually diagnostic in sirenians are determined. However, the holotype material of “<jats:italic>H.</jats:italic>” <jats:italic>antillense</jats:italic> is not informative enough and, as such, neither can be assigned to any known species nor is it possible to define a taxon that can be clearly distinguished from other species. Unlike other, now revised species originally grouped under “<jats:italic>Halitherium</jats:italic>”, the establishment of a new taxonomic combination for “<jats:italic>H.</jats:italic>” <jats:italic>antillense</jats:italic> is not possible. As a nomenclatural consequence, the name “<jats:italic>H.</jats:italic>” <jats:italic>antillense</jats:italic> is only applicable to a single specimen, the holotype, and declared as a <jats:italic>nomen dubium</jats:italic>.</jats:p&gt

On the invalidity of Halitherium schinzii Kaup, 1838 (Mammalia, Sirenia), with comments on systematic consequences

The holotype of the sirenian species Halitherium schinzii Kaup, 1838 from the Alzey Formation (early Oligocene) of the Mainz Basin, western Germany, is reviewed in detail and revised. It is concluded that the type specimen, an isolated premolar, is non-diagnostic, because it reveals no characters of taxonomic value. Therefore, the taxon name H. schinzii is regarded as a nomen dubium, thus cannot be applied to any currently proposed sirenian species. The name of the genus “Halitherium”, which is based on the type species “H. schinzii”, cannot be applied to other species previously assigned to congeneric taxa. Consequently, taxonomic and systematic re-assessment is required. Due to the fact that “Halitherium” is the taxonomical basis of the Halitheriinae, conclusions are drawn on the inappropriateness of this subfamily

Data from: Evidence for two sympatric sirenian species (Mammalia, Tethytheria) in the early Oligocene of Central Europe

The early Oligocene (Rupelian) sirenian Halitherium schinzii Kaup, 1838, which represents the type species of the genus Halitherium Kaup, 1838, is revised herein based on a morphological re-evaluation of skeletal material originally assigned to this taxon. This study provides new and comprehensive information on the cranial and postcranial anatomy and allows the distinction of two sympatric species. Following a recent approach on the invalidity and subsequent rejection of H. schinzii Kaup, 1838, Kaupitherium gruelli new genus new species is established on the basis of a nearly complete holotype. The second taxon resembles K. gruelli n. sp. in a number of skeletal features, such as reduced nasals and absence of the canines, but can be clearly distinguished mainly by the post-canine dental formula and the supraoccipital morphology. The diagnostic skullcap of a species formerly synonymized under “H. schinzii” is re-validated as the holotype of K. bronni (Krauss, 1858). On the basis of paleoecological implications, a hypothesis is established to explain the overlapping stratigraphic and biogeographic occurrences (i.e., sympatry of both taxa). A diagnosis and up-to-date synonymy complement the taxonomical information. The revision of “H. schinzii” provides new data on the past sirenian diversity and forms the basis for a taxonomic and systematic re-evaluation of species originally grouped in the genus “Halitherium.

A taxonomic and morphological re-evaluation of “Halitherium” cristolii Fitzinger, 1842 (Mammalia, Sirenia) from the late Oligocene of Austria, with the description of a new genus

The fossil sirenian material from the upper Oligocene Linz Sands of Upper Austria is reviewed and re-described in detail following a recent approach on the invalidity of the genus Halitherium Kaup, 1838. This morphological study provides the first evidence for the synonymy of “Halitherium” cristolii Fitzinger 1842, “H.” abeli Spillmann, 1959 and “H.” pergense (Toula, 1899), supporting the hypothesis that only a single species inhabited the late Oligocene shores of present-day Upper Austria. In the course of the taxonomic revision of the “Halitherium” species-complex, this taxon is now assigned to the new genus Lentiarenium Voss gen. nov. It represents a more derived sirenian compared to Eocene and early Oligocene taxa distributed across Central Europe and North Africa, which is in accordance with the stratigraphical data. An updated inventory list of all identifiable and referable skeletal material is provided, including a detailed synonymy list for the new taxonomic combination

A taxonomic and morphological re-evaluation of “Halitherium” cristolii Fitzinger, 1842 (Mammalia, Sirenia) from the late Oligocene of Austria, with the description of a new genus

The fossil sirenian material from the upper Oligocene Linz Sands of Upper Austria is reviewed and re-described in detail following a recent approach on the invalidity of the genus Halitherium Kaup, 1838. This morphological study provides the first evidence for the synonymy of “Halitherium” cristolii Fitzinger 1842, “H.” abeli Spillmann, 1959 and “H.” pergense (Toula, 1899), supporting the hypothesis that only a single species inhabited the late Oligocene shores of present-day Upper Austria. In the course of the taxonomic revision of the “Halitherium” species-complex, this taxon is now assigned to the new genus Lentiarenium Voss gen. nov. It represents a more derived sirenian compared to Eocene and early Oligocene taxa distributed across Central Europe and North Africa, which is in accordance with the stratigraphical data. An updated inventory list of all identifiable and referable skeletal material is provided, including a detailed synonymy list for the new taxonomic combination

SuppIementary data set 1-4

The Supplementary data set 1-4 includes material referred to the newly introduced species Kaupitherium gruelli n. gen. and n. sp. and Kaupitherium bronni (Krauss, 1858) as well as cranial, mandibular, dental, and postcranial measurements of the respective species

New findings of Prototherium ausetanum (Mammalia, Pan-Sirenia) from paving stones in Girona (Catalonia, Spain)?

Taxonomic and morphological approaches on Eocene sirenians from Catalonia (Spain) benefit from a newly discovered specimen found in a quite unusual locality, the pedestrian zone in the city of Girona. Two fossil-bearing limestone slabs from middle Eocene (Bartonian) layers of a quarry in the wider surrounding area north-west of Barcelona, were CT-scanned in the Clínica Girona to enhance more detailed investigations. Post-processing of the scans and, as far as possible, 3D-reconstruction of the preserved elements in the slabs was performed at Museum für Naturkunde Berlin. Thereby, a skull of a Dugong specimen was used as a reference point. Based on the combined analysis of macroscopic and CT-data, the specimen most likely represents Prototherium ausetanum Balaguer & Alba, 2016 and complements the available information of the holotype and hitherto only known specimen of that species. The Girona specimen is an adult, but small individual that corroborates P. ausetanum as a generally small-sized species compared to other known Prototherium taxa

Stomach contents of the archaeocete Basilosaurus isis: Apex predator in oceans of the late Eocene.

Apex predators live at the top of an ecological pyramid, preying on animals in the pyramid below and normally immune from predation themselves. Apex predators are often, but not always, the largest animals of their kind. The living killer whale Orcinus orca is an apex predator in modern world oceans. Here we focus on an earlier apex predator, the late Eocene archaeocete Basilosaurus isis from Wadi Al Hitan in Egypt, and show from stomach contents that it fed on smaller whales (juvenile Dorudon atrox) and large fishes (Pycnodus mokattamensis). Our observations, the first direct evidence of diet in Basilosaurus isis, confirm a predator-prey relationship of the two most frequently found fossil whales in Wadi Al-Hitan, B. isis and D. atrox. This extends our understanding of their paleoecology. Late Eocene Basilosaurus isis, late Miocene Livyatan melvillei, and modern Orcinus orca are three marine apex predators known from relatively short intervals of time. Little is known about whales as apex predators through much of the Cenozoic era, and whales as apex predators deserve more attention than they have received