Hebert Campos - Academia.edu (original) (raw)

Papers by Hebert Campos

Scientific Reports

Pterosaurs thrived in and around water for 160 + million years but their take-off from water is p... more Pterosaurs thrived in and around water for 160 + million years but their take-off from water is poorly understood. A purportedly low floating position and forward centre of gravity barred pterosaurs from a bird-like bipedal running launch. Quadrupedal water launch similar to extant water-feeding birds and bats has been proposed for the largest pterosaurs, such as Anhanguera and Quetzalcoatlus. However, quadrupedal water launch has never been demonstrated in smaller pterosaurs, including those living around the Tethys Sea in the Late Jurassic Solnhofen Lagoon. Using Laser-Stimulated Fluorescence, we singled out aurorazhdarchid specimen MB.R.3531 that alone preserved specific soft tissues among more than a dozen well-preserved Solnhofen pterosaur specimens. These soft tissues pertain to primary propulsive contact surfaces needed for quadrupedal water launch (pedal webbing and soft tissues from an articulated forelimb) that permit robust calculations of its dynamic feasibility without ...

Nature

Remarkably well-preserved soft tissues in Mesozoic fossils have yielded substantial insights into... more Remarkably well-preserved soft tissues in Mesozoic fossils have yielded substantial insights into the evolution of feathers1. New evidence of branched feathers in pterosaurs suggests that feathers originated in the avemetatarsalian ancestor of pterosaurs and dinosaurs in the Early Triassic2, but the homology of these pterosaur structures with feathers is controversial3,4. Reports of pterosaur feathers with homogeneous ovoid melanosome geometries2,5 suggest that they exhibited limited variation in colour, supporting hypotheses that early feathers functioned primarily in thermoregulation6. Here we report the presence of diverse melanosome geometries in the skin and simple and branched feathers of a tapejarid pterosaur from the Early Cretaceous found in Brazil. The melanosomes form distinct populations in different feather types and the skin, a feature previously known only in theropod dinosaurs, including birds. These tissue-specific melanosome geometries in pterosaurs indicate that m...

The group Tapejaridae forms a clade of toothless pterosaurs easily recognized by their premaxilla... more The group Tapejaridae forms a clade of toothless pterosaurs easily recognized by their premaxillary sagittal crests and particularly large nasoantorbital fenestrae. The tapejarids represent the most representative group of pterosaurs from the Lower Cretaceous Crato Formation of the Araripe Basin (Northeastern Brazil). The holotype of the large tapejarid Tupandactylus imperator Campos and Kellner, 1997 is known by two main slabs from the New Olinda Member of the Crato Formation, however, only one of the slabs containing the sagittally bipartite skull is referred to the holotype of Tupandactylus imperator, remain the counter-slab be properly described. The cotype is fragmented in several broken pieces and presents a significative number of cranial elements. A medial internasal septum completely preserved inside the nasoantorbital fenestra is reported for the first time for pterosaurs. The exceptional preservation of a collagenous septum and other integumentary structures visible in th...

The posterior part of a skull from a tapejarid pterosaur was studied for the exceptional preserva... more The posterior part of a skull from a tapejarid pterosaur was studied for the exceptional preservation of its soft-tissues. The specimen comes from the Early Cretaceous (Aptian) Crato Formation of northeastern Brazil. It shows a peculiar soft sagittal crest that gives new information about the anatomy and the diversity of tapejarids. The specimen lies on five limestone slabs. The bony part comprised the posterior part of the skull, with the braincase and one complex of three dorsally oriented and associated bony crests. The crest consists of a huge and elongated parietal crest, a trabecular frontal crest, and an occipital spine. The specimen preserves the posterior parts of the nasoantorbital fenestra and orbit. The soft cranial crest is characterized by a multilinear dorsal crest with almost parallel fibres, which curve posteriorly. Pigment organelles – melanosomes – were observed in the crest as well as ‘hair-like’ fibres (pycnofibres). They present diverse shapes and sizes, sugges...

National geographic

66 миллионов лет назад птерозавры вымерли, но и сегодня они остаются самыми загадочными и несураз... more 66 миллионов лет назад птерозавры вымерли, но и сегодня они остаются самыми загадочными и несуразными существами, когда-либо жившими на земле. влад константинов 3-D реконструкции птерозавра абакара смотрите на iPad. Вместе с двумя бразильскими палеонтологами Константинов представил 3D-модель ранее неиз-вестного вида птерозавра. Для палеохудожника создание первой в мире реконструкции нового для науки существа – своего рода привилегия. Скелет абакара, или Abaquar romualdoensis, – так был назван крылатый ящер с огромной гипер-трофированной мордой – ученые обнаружили в Южной Америке в формации Сантана бассейна реки Арарипе (иллюстрация на стр. 122–123). За последние 40 лет этот регион на северо-востоке Бразилии подарил палеонтологам больше двух десятков новых видов птерозавров. Почему-то птерозавров часто считают чем-то вроде летающих динозавров. На самом деле эти загадочные животные составляли другой отряд и были скорее крылатыми современ-никами динозавров, но вовсе не их аналогом. Точ...

Background. The Sousa Formation contains the richest dinosaur ichnofauna from the Early Cretaceou... more Background. The Sousa Formation contains the richest dinosaur ichnofauna from the Early Cretaceous Rio do Peixe Basin, Northeastern Brazil. Occurs eventually ornithopod tracks, which are found also in the Antenor Navarro and Piranhas Formations. Together with one trackway from the Botucatu Formation, some isolated tracks from the Cenomanian São Luís Basin, and some trackways from the Early Cretaceous Corda Formation, at the moment, these occurrences indicates the only definitive presence of ornithopods in the Mesozoic of Brazil. Material & Methods. In 2015, a fieldwork was held to investigate potential dinosaur tracks in new ichnosites from the Sousa Formation. All the tracks were photographed individually using a digital camera Nikon Coolpix P520. The paleoichnological terminology and morphometric parametrers follows Thulborn (1990), Marty (2008) and Castanera et al. (2013). A plastic sheet was used for drawing the tracks. Directions and measurements of each dinosaur track, as well...

Biologia

A historic specimen described for the first time revealed important autapomorphic characters, per... more A historic specimen described for the first time revealed important autapomorphic characters, permitting the definition of a new species, Javelinadactylus sagebieli gen. n. et sp. n., which represents the second toothless species from the Javelina Formation, Big Bend National Park of West Texas (United States of America). The remains of J. sagebieli (Azhdarchoidea: Tapejaridae) were found in 1986, but were never properly studied, and its taxonomic affinity remains undefined. The description is based on a partially articulated skull and mandible, which offer information on the anatomy of a single azhdarchoid pterosaur. J. sagebieli exhibit a large nasoantorbital fenestra, a rostral index of medium value and is assigned to the clade Thalassodrominae, a group of tapejarid pterosaurs that were reported exclusively from the Romualdo Formation of Brazil, with only two genera known. Thalassodromines are characterized by a typical cranial configuration with toothless jaws and a high and wide premaxilla bar, formed by sub-parallel or parallel borders. The new specimen described here represents the first record of the Tapejaridae group in the Maastrichtian of North America, and the cranial morphology of the new taxon increase the richest of the diversity of the azhdarchoid pterosaurs during the end of the Late Cretaceous, suggesting that the tapejarids were still diversifying in the Maastrichtian.

Body imprints and tracks attributed to large crocodylians from the Lower Cretaceous Sousa Formati... more Body imprints and tracks attributed to large crocodylians from the Lower Cretaceous Sousa Formation of Brazil are described and interpreted as having been produced in a subaqueous environment. In addition to the crocodylian tracks, the assemblage also comprises isolated tracks from medium-sized theropods. The studied crocodylian traces are interpreted as subaqueous traces possibly produced by Mesoeucrocodylia crocodyles, during half-swimming and resting next to the margin of a lake. This is the first record of crocodylian traces in Brazil and confirms the potential for finds of new ichnosites in the Rio do Peixe basins of northeastern Brazil.

Historical Biology, 2011

Historical Biology, 2014

Numerous taxa make up the Early Cretaceous fauna of Brazil, including Ornithocheiroidea, Tapejari... more Numerous taxa make up the Early Cretaceous fauna of Brazil, including Ornithocheiroidea, Tapejaridae, Thalassodromidae, Chaoyangopteridae and a purported member of Azhdarchidae. Dsungaripteridae has only been tentatively assumed to be present in the form of 'Santanadactylus' spixi. New study of NMSG SAO 251093 (a specimen referred to Thalassodromeus sethi) suggests it is a previously unknown species of dsungaripterid, Banguela oberlii, tax. nov., differing from Thalassodromeus and other pterosaurs from the Early Cretaceous of Brazil by a unique combination of characters, including an upturned jaw tip, a short dorsal mandibular symphyseal shelf (dmss), and an autapomorphic thin crest placed halfway along the fused mandibular symphysis without a keel along the ventral margin of the jaw. B. oberlii, tax. nov., is referred to Dsungaripteridae based on a dmss no longer than the ventral shelf, U-shaped caudal margin of the ventral shelf and lateral margins of the mandibular symphysis concave in dorsal view. B. oberlii, tax. nov., is the youngest known dsungaripterid, and expands known morphological diversity in the clade as well as the Early Cretaceous pterosaur fauna of South America.

Durante sua deposição sedimentar no Cretáceo Inferior, o complexo de bacias do Rio do Peixe na po... more Durante sua deposição sedimentar no Cretáceo Inferior, o complexo de bacias do Rio do Peixe na porção oriental da América do Sul apresentava uma estreita relação geográfica e união com a África na pré-abertura do Oceano Atlântico. Evidentemente o intercâmbio faunístico (incluindo os dinossauros) era uma característica nas bacias do Rio do Peixe e os depósitos africanos.

A new specimen of the Early Cretaceous azhdarchoid Tapejara wellnhoferi is described from the Rom... more A new specimen of the Early Cretaceous azhdarchoid Tapejara wellnhoferi is described from the Romualdo Member of the Santana Formation, NE Brazil, providing the first detailed account of the postcranial skeleton. Although limited in its preservation, the osteology is typical of other azhdarchoid pterosaurs from these deposits and represents a juvenile animal with a relatively small wing span of , 1.5 m. The ratios of the pedal elements are identical to those noted for larger, indeterminate azhdarchoids of the Nova Olinda Member of the Crato Formation, where the unguals of the pes are greatly enlarged relative to those of the ornithocheiroids that co-inhabited the Santana lagoon. The ratios of these elements suggest that, as part of a larger suite of characters, these animals were likely better adapted for life on the ground than their ornithocheiroid relatives.