Flaviana Jorge de Lima

A new angiosperm from the Crato Formation (Araripe Basin, Brazil) and comments on the Early Cretaceous Monocotyledons

The Crato Formation paleoflora is one of the few equatorial floras of the Early Cretaceous. It is diverse, with many angiosperms, especially representatives of the clades magnoliids, monocotyledons and eudicots, which confirms the assumption that angiosperm diversity during the last part of the Early Cretaceous was reasonably high. The morphology of a new fossil monocot is studied and compared to all other Smilacaceae genus, especially in the venation. Cratosmilax jacksoni gen. et sp. nov. can be related to the Smilacaceae family, becoming the oldest record of the family so far. Cratosmilax jacksoni is a single mesophilic leaf with entire margins, ovate shape, with acute apex and base, four venation orders and main acrodromous veins. It is the first terrestrial monocot described for the Crato Formation, monocots were previously described for the same formation, and are considered aquatics. Cratosmilax jacksoni is the first fossil record of Smilacaceae in Brazil, and the oldest record of this family.

Paleohistology of Susisuchus anatoceps (Crocodylomorpha, Neosuchia): Comments on Growth Strategies and Lifestyle.

Susisuchus anatoceps is a neosuchian crocodylomorph lying outside the clade Eusuchia, and associated with the transition between basal and advanced neosuchians and the rise of early eusuchians. The specimen MPSC R1136 comprises a partially articulated postcranial skeleton and is only the third fossil assigned to this relevant taxon. Thin sections of a right rib and right ulna of this specimen have been cut for histological studies and provide the first paleohistological information of an advanced non-eusuchian neosuchian from South America. The cross-section of the ulna shows a thick cortex with 17 lines of arrested growth (LAGs), a few scattered vascular canals, and primary and secondary osteons. This bone has a free medullary cavity and a spongiosa is completely absent. Thin sections of the rib show that remodeling process was active when the animal died, with a thin cortex and a well-developed spongiosa. In the latter, few secondary osteons and 4 LAGs were identified. According to the observed data, Susisuchus anatoceps had a slow-growing histological microstructure pattern, which is common in crocodylomorphs. The high number of ulnar LAGs and the active remodeling process are indicative that this animal was at least a late subadult, at or past the age of sexual maturity. This contradicts previous studies that interpreted this and other Susisuchus anatoceps specimens as juveniles, and suggests that full-grown adults of this species were relatively small-bodied, comparable in size to modern dwarf crocodiles.

Evidence of plant–insect interaction in the Early Cretaceous Flora from the Crato Formation, Araripe Basin, Northeast Brazil

Abstract The analysis of insect-plant interaction can be provide paleoecological and paleoenvironmental important data for understanding the co-evolution between plants and insects. Since the appearance of the first evidence of leaves damaged by insects, these organisms have evolved together. In the Araripe Basin, the Crato Formation stands out by having abundance and diversity of fossils species of plants and insects. In this work they are documented interaction records in specimens of ferns, gymnosperms and angiosperms, showing a wide variety of types of interactions. Here we analyze 56 fossil specimens from the collections of the Museum of Paleontology and the Laboratory of Paleontology of the Universidade Regional do Cariri. The types of damage identified in this study is insect galls, leaf margin feeding (herbivory), leaf mines, oviposition of insects and skeletonization, which are present in 19 specimens. This analysis in search for evidences of plant–insect interaction contributes with new interaction patterns for the Crato Formation. Although the low sample rate, the new registers for plant-insect association were compared to records from different cretaceous basins. This suggests new possibilities in the studies for ecological relations and coevolutionary plant-insect during the Cretaceous. In addition, a new type of damage is identified in a pteridophyte.