Arlenea delicata gen. et sp. nov., a new ephedroid plant from the Early Cretaceous Crato Formation, Araripe Basin, Northeast Brazil.

Ephedroid macrofossils have been widely documented in Cretaceous deposits, including numerous from the Lower Cretaceous Yixian Formation of NE China. However, few ephedroid macrofossils have been reported from South America. Herein, we describe a new plant of the family Ephedraceae, Arlenea delicata gen. et sp. nov., from the Lower Cretaceous Crato Formation of the Araripe Basin, Northeast Brazil, based on the vegetative and reproductive structures. It has the typical morphological characteristics of ephedroid plants, including fertile reproductive branches, opposite phyllotaxy, terminal female cones, a sympodial branching system, longitudinally striated internodes, and swollen nodes. Our new finding is unusual in having inner chlamydosperms subtended by two pairs of bracts, reproductive units connected to branches through swollen receptacles and a smooth seed surface. This new ephedroid taxon from the Crato Formation increases our understanding of plant diversity of this group during the Early Cretaceous. Furthermore, the general morphology (fleshy bracts and enlarged receptacles) of this new fossil discovery indicates that seeds of this plant may have been dispersed by animals such as pterosaurs (mainly the Tapejaridae) and birds (Enantiornithes and Ornituromorpha). If true, this would explain the cosmopolitan distribution of Ephedraceae in the Lower Cretaceous.

Osteohistology and microanatomy of a new specimen of Cearachelys placidoi (Testudines: Pleurodira) a side-necked turtle from the lower Cretaceous of Brazil.

Pelomedusoides had a recognised diverse Early Cretaceous fauna of turtles in Northeast Brazil. Within them, the bothremydid Cearachelys placidoi has a relatively abundant record. This diversity contrasts with the scarcity of osteohistological studies in this group. The relatively well-preserved shell of C. placidoi (UFRPE 5600), from the Aptian age of Araripe Basin, is studied here for the purpose of filling this gap. We performed the osteohistological description of the plastron of a new specimen of C. placidoi. Also, to conduct a comparative study, we carried out histological sections in bones of the recent chelid Phrynops sp. Our histological findings indicate similarities between the histological pattern of freshwater turtles and the coastal marine C. placidoi. Moreover, osteohistological features imply metaplastic incorporation of dermal interwoven structural fiber bundles. Lastly, the xiphiplastron of C. placidoi shows an increase of bone compactness over its craniocaudal axis. This microanatomical feature is exclusive to Cearachelys so far.

Os Pelomedusoides tiveram uma reconhecida biodiversidade durante o Cretáceo inferior do Nordeste brasileiro. Dentre eles, o bothremydideo, Cearachelys placidoi tem um registro relativamente abundante. Essa diversidade contrasta com a escassez de estudos osteohistológicos neste grupo. Em relativa boa preservação, o casco de C. placidoi (UFRPE 5600), de idade aptiana da Bacia do Araripe, é estudado aqui com o propósito de preencher esta lacuna. Nós realizamos a descrição osteohistológica do plastrão do novo espécime de C. placidoi. Ademais, para conduzir o estudo comparativo, nós realizamos secções histológicas em ossos do quelídeo recente, Phrynops sp. Nossas descobertas histológicas indicam similaridades entre o padrão histológico das tartarugas de água doce e da marinha costeira C. placidoi. Além disso, as características osteohistológicas implicam na incorporação metaplástica de feixes de fibras dérmicas entrelaçadas. Finalmente, o xifiplastrão de C. placidoi mostra um aumento da compactação óssea ao longo do eixo craniocaudal. Esta característica microanatômica é exclusiva de Cearachelys até o momento.

Author Correction: The first theropod dinosaur (Coelurosauria, Theropoda) from the base of the Romualdo Formation (Albian), Araripe Basin, Northeast Brazil.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The first theropod dinosaur (Coelurosauria, Theropoda) from the base of the Romualdo Formation (Albian), Araripe Basin, Northeast Brazil.

The Romualdo Formation (Araripe Basin) is worldwide known for the large number of well-preserved fossils but the dinosaur record is rather scarce. Here we describe a new coelurosaur, which is the first tetrapod recovered from the basal layers of this stratigraphic unit that consist of dark shales. Aratasaurus museunacionali gen. et sp. nov. is known by an incomplete but articulated right hind limb with the distal portion of the femur, proximal half of tibia and incomplete pes. The new species differs from other coelurosaurs by a medial fossa in the tibia and digits II, III and IV being symmetric. The phylogenetic analysis recovered Aratasaurus museunacionali closely related to Zuolong salleei, forming a basal coelurosaur lineage. The paleohistology indicate that the specimen is a juvenile, with an estimated body length around 3.12 m. The new taxon represents the first occurrence of basal coelurosaurians in the Araripe Basin and suggests a widespread distribution of this group during the Lower Cretaceous.

New findings on Dendrobranchiata fossils of the Romualdo Formation, Araripe Basin, Northeast of Brazil.

The Araripe Basin is the largest inland basin in northeastern Brazil is known for its preservation excellent, number of specimens and variety of fossil species. The Araripe Basin stands out for its fossiliferous content of well known fossil groups, from vertebrates to invertebrates, especially decapod crustaceans. Thus, a morphological re-description of two shrimp species, Paleomattea deliciosa and Araripenaeus timidus, was carried out through taxonomic and morphoanatomical analysis. The mechanical preparation methodology was adopted in the laboratory, with a total of 58 specimens were analyzed and photographed to determine which characters were preserved or not, as well as to compared these with holotypes.                The results show that characters such as carapaces complete with the presence of spines, pleon with six somites, pereiopods and pleopods, in addition to uropods and telson were preserved in Paleomattea deliciosa, while carapaces, pleon complete and pereiopods were preserved in Araripenaeus timidus. Thus, the current study provides new species information which can be used in future species-type studies and contributes to a better understanding of these Araripe species.

A new genus and species of Solenoceridae (Crustacea, Decapoda, Dendrobranchiata) from the Cretaceous (Aptian/Albian) of the Araripe Sedimentary Basin, Brazil.

The first fossil Solenoceridae found from the Cretaceous (Aptian-Albian) is described in the Araripe Sedimentary basin, Priorhyncha feitosai n. gen. n. sp. The material was collected in the strata of the Romualdo Formation, municipality of Trindade, Pernambuco. Characters that permit placement of the new species in Solenoceridae are: a short, dorsally serrated rostrum; a marked cervical groove; and the presence of an antennal spine. Those characters are also diagnostic for Priorhyncha feitosai n. gen. n. sp. when compared to the other Dendrobranchiata shrimp described from this basin.

Oxygen isotope fractionation between bird bone phosphate and drinking water.

Oxygen isotope compositions of bone phosphate (δ18Op) were measured in broiler chickens reared in 21 farms worldwide characterized by contrasted latitudes and local climates. These sedentary birds were raised during an approximately 3 to 4-month period, and local precipitation was the ultimate source of their drinking water. This sampling strategy allowed the relationship to be determined between the bone phosphate δ18Op values (from 9.8 to 22.5‰ V-SMOW) and the local rainfall δ18Ow values estimated from nearby IAEA/WMO stations (from -16.0 to -1.0‰ V-SMOW). Linear least square fitting of data provided the following isotopic fractionation equation: δ18Ow = 1.119 (±0.040) δ18Op - 24.222 (±0.644); R 2 = 0.98. The δ18Op-δ18Ow couples of five extant mallard ducks, a common buzzard, a European herring gull, a common ostrich, and a greater rhea fall within the predicted range of the equation, indicating that the relationship established for extant chickens can also be applied to birds of various ecologies and body masses. Applied to published oxygen isotope compositions of Miocene and Pliocene penguins from Peru, this new equation computes estimates of local seawater similar to those previously calculated. Applied to the basal bird Confuciusornis from the Early Cretaceous of Northeastern China, our equation gives a slightly higher δ18Ow value compared to the previously estimated one, possibly as a result of lower body temperature. These data indicate that caution should be exercised when the relationship estimated for modern birds is applied to their basal counterparts that likely had a metabolism intermediate between that of their theropod dinosaur ancestors and that of advanced ornithurines.