4 research outputs found
Novel information on the cranial anatomy of the tapejarine pterosaur Caiuajara dobruskii
Caiuajara dobruskii is a tapejarid pterosaur from the Cretaceous of the 'Cemitério dos Pterossauros' (pterosaur graveyard) site, a unique pterosaur bonebed which is located at the municipality of Cruzeiro do Oeste (Paranå, Brazil). Preliminary inferences on Caiuajara morphology were founded on a few partial skeletons, with no detail on the skull anatomy. Here we describe a new specimen from the pterosaur graveyard site, which corresponds to the most complete skull of Caiuajara dobruskii known so far. Furthermore, we describe and compare other specimens including the holotype, a paratype, and several other undescribed specimens. The new specimen preserves the posterior portion of the skull, allowing a better comprehension of its morphology and provides an appreciation of the anatomic structures of the basicranium, enabling better interpretation of this region. We also described the lower jaw of Caiuajara, reporting a unique feature of its symphyseal which adds to the diagnosis for the species. A variability in the premaxillary crest is also noted in different specimens of Caiuajara, which might be interpreted as sexual dimorphism or ontogenetic variability. Therefore, those new findings allow a better comprehension of its skull and enables a more precise comparison between the skulls of those extinct flying reptiles
The Lontras Shale (Permian, ParanĂĄ Basin) and its Fossils: Discovery, Taxonomic Identification and Present Knowledge
The Shaler Memorial Fund created in 1907 by students and admirers of the geologist Nathaniel Southgate Shaler, professor
from Harvard University, allowed in its first contribution to fostering research, the organization of an expedition to the South and
Southeast of Brazil. The expedition had the purpose to confirm Nathaniel`s ideas about the existence of glacial layers older then the
Pleistocene. Led by the North American geologist Jay Backus Woodworthy and counting with participation of the Brazilian geologist
Euzébio de Oliveira, the expedition not only proved the presence of glacial evidence but also discovered an intercalated fossiliferous
marine shale, later known as Lontras Shale, Itararé Group. The fossils, initially studied by the American paleontologist Rudolf
Ruedemann and by Euzébio de Oliveira, had its studies intensified from the 1980s with the identification of new outcrops and due the
new data of the geological evolution of the carboniferous and permian sedimentary sucessions of the ParanĂĄ Basin. Economic disputes
and discussion about the preservation of Lontras Shale outcrops, besides the discovered of new site namely as CAMPĂLEO, have
reactivated the scientific interest about this unit and its paleontological content, increasing its studies. Poorly known by the Brazilian
academic community, the historical context of the Lontras Shale is here reported, highlighting the importance of the Shale Memorial
Fund as responsible for the geological and paleontological discoveries that have followed, for more than a century
First description of scleractinian corals from the Santa Marta and Snow Hill Island (Gamma Member) formations, Upper Cretaceous, James Ross Island, Antarctica
Antarctic corals are known from the Upper Cretaceous Santa Marta Formation (Santonianâearly Campanian) and Gamma Member (late Campanian) of Snow Hill Island Formation (late Campanianâearly Maastrichtian) but they have not so far been taxonomically described. We describe three corals taxa based on 29 specimens collected in 2007 and 2016 on James Ross Island (northeast of the Antarctic Peninsula). They represent the first formal record of scleractinian corals from the Santa Marta Formation, identified as Caryophylliidae indet. and Gamma Member of Snow Hill Island Formation, identified as ?Astreopora sp. and Fungiacyathus deltoidophorus. The family Caryophylliidae and the genus Astreopora were not restricted to the Weddellian Biogeographic Province but the species Fungiacyathus deltoidophorus was endemic to Antarctica during the Cretaceous. The genus Fungiacyathus and the family Caryophylliidae thrive in Antarctica until the present day. Fungiacyathus occurred in shallower environments during the late Campanian than today. No specimens related to Astreopora have yet to be found in Antarctica after the late Campanian. This can be explained by the capacity of Fungiacyathus and Caryophyllidae to endure cold waters, since they are asymbiotic corals. The symbiotic ?Astreopora sp., due to its sensitivity to low temperatures, became extinct in this continent as soon as the Antarctic waters began to cool, around the Campanian/Maastrichtian. The presence of ?Astreopora sp. in Gamma Member of Snow Hill Island Formation may represents the first occurrence of this genus in Antarctica and the oldest record of this genus in the Southern Hemisphere