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Abstract Fossil vertebrates from Antarctica are considerably rare, hampering our understanding of the evolutionary history of the biota from that continent. For several austral summers, the PALEOANTAR project has been carrying out fieldwork in the Antarctic Peninsula in search for fossils, particularly Cretaceous vertebrates. Among the specimens recovered so far are two bones referable to Pterosauria, more specifically to the Pterodacyloidea, the first volant reptiles from Antarctica to be fully described. MN 7800-V (part and counterpart) was recovered from a moraine at the Abernathy Flats (Santa Marta Formation, Lachman Crags Member, Santonian-Campanian) on James Ross Island. It is interpreted as the distal articulation of a first phalanx of the wing finger, representing an animal with an estimated wingspan between 3 and 4 m. The second specimen (MN 7801-V) comes from Vega Island (Snow Hill Island Formation, Maastrichtian) and is identified as a wing metacarpal IV of an animal with an estimated wingspan from 4 to 5 m. These occurrences show that pterodactyloids inhabited the Antarctic Peninsula at least during the Upper Cretaceous and demonstrate that large pterosaurs were widespread through all parts of the planet during that period.

A contraparte de um espécime anteriormente descrito, contendo uma fêmea de pterossauro não-pterodactiloide com um ovo, revela a existência de um segundo ovo, este situado dentro da cavidade corporal desta fêmea prenhe. O exemplar demonstra claramente que os pterossauros possuíam dois ovidutos funcionais, e evidencia que a redução de um oviduto não foi um pré-requisito para o desenvolvimento do voo ativo pelo menos neste grupo. A análise da composição de um dos ovos sugere a ausência de uma camada externa formada por carbonato de cálcio. Seções histológicas de um fêmur não registram osso medular e demonstram que este pterossauro atingiu maturidade reprodutiva antes da maturidade óssea. O presente estudo evidencia que os pterossauros punham ovos de tamanho ainda menor do que se supunha e que desenvolveram uma estratégia reprodutiva mais similar a dos répteis basais do que a das aves. Se pterossauros eram altamente precociais ou necessitavam de cuidado parental ainda está aberto à discussão.

The counterpart of a previously described non-pterodactyloid pterosaur with an egg revealed the presence of a second egg inside the body cavity of this gravid female. It clearly shows that pterosaurs had two functional oviducts and demonstrates that the reduction of one oviduct was not a prerequisite for developing powered flight, at least in this group. Compositional analysis of one egg suggests the lack of a hard external layer of calcium carbonate. Histological sections of one femur lack medullary bone and further demonstrate that this pterosaur reached reproductive maturity before skeletal maturity. This study shows that pterosaurs laid eggs even smaller than previously thought and had a reproductive strategy more similar to basal reptiles than to birds. Whether pterosaurs were highly precocial or needed parental care is still open to debate.

Although important dinosaur specimens have been recently described from Brazil, the theropod record in this county is still rather scarce, particularly from Cretaceous strata. Here we describe a complete right tibia (MCT 1783-R) from the Marilia Formation (Maastrichtian, Bauru Basin) near Peiropolis (Uberaba, Minas Gerais). This is the best theropod specimen recovered from this unit after five decades of collecting. MCT 1783-R shows a well developed cnemial crest with a lobular distal end, that projects significantly above the proximal articular surface, features that are characteristic of the Abelisauroidea. It further shows unique characters such as a marked asymmetry of lateral and medial condyles in posterior view, and a very deep triangular articular face for the astragalus, suggesting that it represents a new taxon.

A pesar de que importantes especímenes de dinosaurios de Brasil se han descrito recientemente, el registro de terópodos en este país es todavía bastante escaso, especialmente en los estratos del Cretácico. Aqui reportamos una tibia derecha completa (MCT 1783-R) de la Formación Marilia (Maastrichtiano, Cuenca Bauru) en el área de Peirópolis (Uberaba, Minas Gerais). Este es el mejor material de terópodo recuperado de esta unidad en cinco décadas de recolección. MCT 1783-R muestra una cresta cnemial bien desarrollada con un extremo distal lobular, proyectado significativamente por encima de la superficie articular proximal, los cuales son rasgos característicos de Abelisauroidea. Muestra, además, algunas características únicas, como una marcada asimetría de los cóndilos medial y lateral en el lado posterior y una cara triangular articular muy profunda por el astrágalo, sugiriendo que representa un nuevo taxón.

Um grande pterossauro (MN 6594-V) da Formação Romualdo (Aptiano/Albiano), Grupo Santana, Bacia do Araripe, é descrito. O espécime é referido a Tropeognathus cf. T. mesembrinus principalmente pela crista frontoparietal baixa e obtusa, por um número comparativamente baixo de dentes e pela inclinação da porção dorsal da região occipital. Duas distintas medidas de envergadura para pterossauros são introduzidas: a envergadura maximizada (maxws), que consiste essencialmente no dobro da soma de todos os elementos da asa e o comprimento da escápula ou do coracóide (o menor de ambos), e a envergadura normal (nws), que aplica um fator de redução (rdc) à envergadura maximizada para compensar as curvaturas naturais da asa. Para pteranodontóides o rfc sugerido é de 5%. No caso de MN 6594-V, maxws e nws correspondem a 8,70 m e 8,26 m, respectivamente, o que faz deste espécime o maior pterossauro coletado do Gondwana até hoje. A extremidade distal de um úmero de maior tamanho (MCT 1838-R) e uma asa parcial (MPSC R 1395) também são aqui descritos, mostrando que pterossauros grandes ou gigantescos formaram uma parcela significativa da fauna de pterossauros da Formação Romualdo. Finalmente, alguns comentários sobre a estabilidade nomenclatural para os depósitos de Santana são feitos.

A very large pterosaur (MN 6594-V) from the Romualdo Formation (Aptian/Albian), Santana Group, Araripe Basin, is described. The specimen is referred to Tropeognathus cf. T. mesembrinus mainly due to the presence of a low and blunt frontoparietal crest, the comparatively low number of teeth and the inclined dorsal part of the occipital region. Two distinct wingspan measurements for pterosaurs are introduced: the maximized wingspan (maxws), which essentially consists of doubling the addition of all wing elements and the length of the scapula or the coracoid (the smaller of the two), and the normal wingspan (nws), which applies a reducing factor (rfc) to the maximized wingspan to account for the natural flexures of the wing. The rfc suggested for pteranodontoids is 5%. In the case of MN 6594-V, the maxws and nws are 8.70 m and 8.26 m, respectively, making it the largest pterosaur recovered from Gondwana so far. The distal end of a larger humerus (MCT 1838-R) and a partial wing (MPSC R 1395) are also described showing that large to giant flying reptiles formed a significant part of the pterosaur fauna from the Romualdo Formation. Lastly, some comments on the nomenclatural stability of the Santana deposits are presented.

Dinosaur research is developing at very high rates around the world resulting in several new discoveries that are improving our understanding of this terrestrial reptilian clade. Except for the last couple years, the studies of Brazilian dinosaurs have not followed this expansive trend, despite the high potential of several dinosaur localities. So far there are only eight described taxa, four in the last year, representing theropod, sauropod, and one possible prosauropod taxa. Except for footprints, there are no records of ornithischian dinosaurs in the country what is at least partially explainable by the lack of continuous vertebrate fossil collecting program in the country. More funding is necessary to improve the research activities in this field.