scholarly journals Arktocara yakataga, a new fossil odontocete (Mammalia, Cetacea) from the Oligocene of Alaska and the antiquity of Platanistoidea

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2321 ◽  
Author(s):  
Alexandra T. Boersma ◽  
Nicholas D. Pyenson

The diversification of crown cetacean lineages (i.e., crown Odontoceti and crown Mysticeti) occurred throughout the Oligocene, but it remains an ongoing challenge to resolve the phylogenetic pattern of their origins, especially with respect to stem lineages. One extant monotypic lineage,Platanista gangetica(the Ganges and Indus river dolphin), is the sole surviving member of the broader group Platanistoidea, with many fossil relatives that range from Oligocene to Miocene in age. Curiously, the highly threatenedPlatanistais restricted today to freshwater river systems of South Asia, yet nearly all fossil platanistoids are known globally from marine rocks, suggesting a marine ancestry for this group. In recent years, studies on the phylogenetic relationships in Platanistoidea have reached a general consensus about the membership of different sub-clades and putative extinct groups, although the position of some platanistoid groups (e.g., Waipatiidae) has been contested. Here we describe a new genus and species of fossil platanistoid,Arktocara yakataga, gen. et sp. nov. from the Oligocene of Alaska, USA. The type and only known specimen was collected from the marine Poul Creek Formation, a unit known to include Oligocene strata, exposed in the Yakutat City and Borough of Southeast Alaska. In our phylogenetic analysis of stem and node-based Platanistoidea,Arktocarafalls within the node-based sub-clade Allodelphinidae as the sister taxon toAllodelphis pratti. With a geochronologic age between ∼29–24 million years old,Arktocarais among the oldest crown Odontoceti, reinforcing the long-standing view that the diversification for crown lineages must have occurred no later than the early Oligocene.

2010 ◽  
Vol 84 (4) ◽  
pp. 695-708 ◽  
Author(s):  
Andrea Jiménez-Sánchez ◽  
Robert L. Anstey ◽  
Beatriz Azanza

The new genus Iberostomata (Bryozoa, Ptilodictyina) from the Cystoid Limestone Formation in the Iberian Chains (NE Spain) is here described and its phylogenetic relationships analyzed using cladistic methods. Twenty-eight identifying characters used in traditional systematics have been codified for nine ptilodictyine families, two timanodictyine families and 34 ptilodictyine genera. The results obtained in this analysis place the new genus Iberostomata and the genus Stellatodictya, traditionally included in the family Ptilodictyidae, in the family Rhinidictyidae, question the validity of the family Intraporidae, question the assignment of Amurodictya and Astrovidictya to the family Stictoporellidae, as well as the assignment of the genera Junggarotrypa, Goniotrypa, and Prophyllodictya to the family Rhinidictyidae, and place the family Phragmopheridae in a uncertain systematic position.


1995 ◽  
Vol 69 (2) ◽  
pp. 376-380 ◽  
Author(s):  
Daniel B. Blake ◽  
Keith Sturgeon

Aldebarania arenitea (Astropectinidae; Asteroidea; Echinodermata) is described from the Rocky Point Member of the Maastrichtian (Upper Cretaceous) Peedee Formation of North Carolina. A turbulent, shallow-water environment is suggested by sedimentary features, a diverse marine fauna, and the morphology of Aldebarania. Aldebarania appears to be a partial ecological equivalent of living Astropecten and Luidia; however, phylogenetic relationships within the Astropectinidae are unstudied and the origin of similarities is unknown.


2010 ◽  
Vol 84 (4) ◽  
pp. 695-708 ◽  
Author(s):  
Andrea Jiménez-Sánchez ◽  
Robert L. Anstey ◽  
Beatriz Azanza

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12074
Author(s):  
Shorouq F. Al-Ashqar ◽  
Erik R. Seiffert ◽  
Dorien de Vries ◽  
Sanaa El-Sayed ◽  
Mohamed S. Antar ◽  
...  

Background The rich rodent assemblages from the Eocene–Oligocene deposits of the Jebel Qatrani Formation (Fayum Depression, Egypt) have important implications for our understanding of the origin and paleobiogeography of Hystricognathi, a diverse clade that is now represented by the Afro-Asiatic Hystricidae, New World Caviomorpha, and African Phiomorpha. Methods Here we present previously undescribed material of the enigmatic hystricognath clade Phiocricetomyinae, from two stratigraphic levels in the lower sequence of the Jebel Qatrani Formation—a new genus and species (Qatranimys safroutus) from the latest Eocene Locality 41 (~34 Ma, the oldest and most productive quarry in the formation) and additional material of Talahphiomys lavocati from that species’ type locality, early Oligocene Quarry E (~31–33.2 Ma). Results The multiple specimens of Qatranimys safroutus from L-41 document almost the entire lower and upper dentition, as well as mandibular fragments and the first cranial remains known for a derived phiocricetomyine. Specimens from Quarry E allow us to expand comparisons with specimens from Libya (late Eocene of Dur at-Talah and early Oligocene of Zallah Oasis) that have been placed in T. lavocati, and we show that the Dur at-Talah and Zallah specimens do not pertain to this species. These observations leave the Fayum Quarry E as the only locality where T. lavocati occurs.


2018 ◽  
Author(s):  
Robert Boessenecker ◽  
R. Ewan Fordyce

The early evolution of toothless baleen whales (Chaeomysticeti) remains elusive despite a robust record of Eocene-Oligocene archaeocetes and toothed mysticetes. Eomysticetids, a group of archaic longirostrine and putatively toothless baleen whales fill in a crucial morphological gap between well-known toothed mysticetes and more crownward Neogene Mysticeti. A historically important but perplexing cetacean is “Mauicetus” lophocephalus (upper Oligocene South Island, New Zealand). The discovery of new skulls and skeletons of eomysticetids from the Oligocene Kokoamu Greensand and Otekaike Limestone permit a redescription and modern reinterpretation of “Mauicetus” lophocephalus, and indicating that this species may have retained adult teeth. A new genus and species, Tokarahia kauaeroa, is erected on the basis of a well-preserved subadult to adult skull with mandibles, tympanoperiotics, and cervical and thoracic vertebrae, ribs, sternum, and forelimbs from the Otekaike Limestone (>25.2 Ma). “Mauicetus” lophocephalus is relatively similar and recombined as Tokarahia lophocephalus. Phylogenetic analysis supports inclusion of Tokarahia within the Eomysticetidae alongside Eomysticetus, Micromysticetus, Yamatocetus, and Tohoraata, and strongly supports monophyly of Eomysticetidae. Tokarahia lacked extreme rostral kinesis of extant Mysticeti and primitively retained a delicate archaeocete-like posterior mandible and synovial temporomandibular joint, suggesting that Tokarahia was capable of at most, limited lunge feeding in contrast to extant Balaenopteridae, and utilized an alternative as-yet unspecified feeding strategy.


2019 ◽  
Vol 94 (3) ◽  
pp. 568-579
Author(s):  
Alexander O. Averianov

AbstractKazachostylops occidentalis Nesov, 1987b, based on partial maxilla and dentary from the upper Paleocene Zhylga locality in South Kazakhstan, is redescribed. A new phylogenetic hypothesis of Arctostylopida is proposed based on phylogenetic analysis of 26 characters and 17 taxa. Kazachostylops is recovered as a sister taxon to the Arctostylopinae, the advanced clade of Asian and North American arctostylopids characterized by pseudohypocone on upper molars and reduced trigonid of lower molars, with the ectolophid being attached labial on the trigonid. Kazachostylops differs from more basal arctostylopids (Asiostylops, Allostylops, Bothriostylops, and Wanostylops) by higher-crowned molars, M1–3 metaconule absent, m1–3 entoconid connected with ectolophid by entolophid, and m2 wider than m1 and m3. Principal component analyses of the upper and lower dentition of arctostylopids show great distinctness of Kazachostylops from other members of the group. The arctostylopid taxa are reviewed, and the new genus Enantiostylops is erected for ‘Sinostylops’ progressus Tang and Yan, 1976 from the lower Eocene of China, because of uniquely concave parastylar area on upper molars.UUID: http://zoobank.org/a46d8f29-fd73-4e59-88dc-fcc55b12d1d3


Zootaxa ◽  
2012 ◽  
Vol 3568 (1) ◽  
pp. 81 ◽  
Author(s):  
MARIANA CHANI-POSSE ◽  
GUY COUTURIER

Delgadobius amazonensis Chani-Posse & Couturier, gen. et sp. nov., a new genus and species of the subtribe Philonthina (tribe Staphylinini) from Amazonia, is described and illustrated. The potential phylogenetic relationships of Delgadobius with other Neotropical genera of Philonthina are discussed. Distributional and bionomic data are also provided. Delgadobius amazonensis is reported in association with four species of palm trees (Arecaceae).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Adele H. Pentland ◽  
Stephen F. Poropat ◽  
Travis R. Tischler ◽  
Trish Sloan ◽  
Robert A. Elliott ◽  
...  

Abstract The Australian pterosaur record is poor by world standards, comprising fewer than 20 fragmentary specimens. Herein, we describe the new genus and species Ferrodraco lentoni gen. et sp. nov., based on the most complete pterosaur specimen ever found in Australia, and the first reported from the Winton Formation (Cenomanian–lower Turonian). The presence of premaxillary and mandibular crests, and spike-shaped teeth with subcircular bases, enable Ferrodraco to be referred to Anhangueria. Ferrodraco can be distinguished from all other anhanguerian pterosaurs based on two dental characters: the first premaxillary and mandibular tooth pairs are small; and the fourth–seventh tooth pairs are smaller than the third and eighth ones. Ferrodraco was included in a phylogenetic analysis of Pterosauria and resolved as the sister taxon to Mythunga camara (upper Albian Toolebuc Formation, Australia), with that clade occupying the most derived position within Ornithocheiridae. Ornithocheirus simus (Albian Cambridge Greensand, England), Coloborhynchus clavirostris (Valanginian Hastings Sands, England), and Tropeognathus mesembrinus (upper Aptian–lower Albian Romualdo Formation, Brazil) were resolved as successive sister taxa, which suggests that ornithocheirids were cosmopolitan during the Albian–Cenomanian. Furthermore, the stratigraphic age of Ferrodraco lentoni (Cenomanian–lower Turonian) implies that anhanguerians might have survived later in Australia than elsewhere.


Zootaxa ◽  
2012 ◽  
Vol 3534 (1) ◽  
pp. 61 ◽  
Author(s):  
JELLE S. ZIJLSTRA

A collection of 17 isolated rodent molars from a cave in the eastern part of Duivelsklip, Curaçao, Dutch West Indies, isdescribed as Dushimys larsi, new genus and species. The new species is characterized by relatively large size, broad mo-lars, absence of mesolophid and presence of anterolophid and anterolabial cingulum on m3, absence of metaloph on M3,and m2 with three roots. Phylogenetic analysis could not conclusively resolve the position of the new species, and it isprovisionally regarded as a representative of an otherwise unknown oryzomyine genus. The material is likely middle Pleistocene in age.


Zootaxa ◽  
2006 ◽  
Vol 1118 (1) ◽  
pp. 57 ◽  
Author(s):  
LIZA GOMEZ-DAGLIO ◽  
ROBERT VAN SYOC

A new genus and species, Lissaclita melaniae (Tetraclitidae), is described from the Gulf of California, Baja California Sur, Mexico. Lissaclita has a secondarily divided single row of parietal tubes without septa, lack of tubes in the radii, diametric shell growth, and a membranous basis. This combination of characters does not agree with any currently described subfamily within the Tetraclitidae. Lacking a detailed phylogenetic analysis of the entire family, we place the new genus in the Tetraclitidae without assigning it to a subfamily.


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