RESUMO
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.
RESUMO
Representatives of the Class Ostracoda are widely used as tools in applied paleoecological and biostratigraphical studies in all continents. In the Araripe Basin, located in the northeastern of Brazil, the Romualdo Formation is one of the most studied, not only for the preservation but also for the abundance of its fossils. The ostracod genus Pattersoncypris Bate, 1972 is well-represented in this formation and it is the most abundant, which reinforces the importance of its taxonomic study. In this work, Pattersoncypris minima sp. nov. is described for the Romualdo Formation as a contribution to the knowledge on Brazilian Cretaceous non-marine ostracods. Taphonomic aspects are also presented, considering the complete ontogenetic stages of the material.
Assuntos
Crustáceos , Fósseis , Animais , BrasilRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
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.
