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Occurrences of young and immature individuals, relatively rare in the fossil record, are important due to the great amount of morphological and evolutionary information they reveal about a lineage's development. Although crocodylomorphs are the most abundant terrestrial vertebrates found in the Bauru Basin, southeastern Brazil, even outnumbering dinosaurian materials, much remains to be understood about their anatomy, ecology, and ontogeny. Egg fragments, nests and nesting sites attributed to Baurusuchus have been previously described, but unfortunately none of these yielded embryonic or hatchling remains. Here, we describe, for the first time, skeletal material of a small notosuchian yearling, recovered from the Adamantina Formation, with osteological features consistent with a baurusuchid affinity. We provide and discuss osteological and histological evidence of its ontogenetic stage, revealing morphological characters distinct from most adult forms, including conspicuous centro-parapophyseal laminae and developed ventral keels. Computerised tomography data also allowed for the identification of incipient ossification and a novel ontogenetic feature in the diminishing volume of the frontal´s internal recesses. Similar materials will increase our understanding of notosuchian ontogeny and diversity, thus requiring growth characters to be integrated into future phylogenies. [ABSTRACT FROM AUTHOR]

Compared with crocodylomorph body fossils, the record of fossil crocodiloid eggs is scarce and poorly understood, a gap partially attributed to their typically thin eggshell, which is not conducive to preservation. A remarkable new association of well-preserved eggs and eggshells from the Adamantina Formation (Bauru Group, Upper Cretaceous) is described and compared to other known materials, while the significance of their unique oological features is discussed. These eggs constitute a new ootaxon, Bauruoolithus fragilis oogen. et oosp. nov., diagnosed by the following characteristics: elongate and elliptical egg with blunt ends; length-to-diameter ratio of 1:0.55; outer surface slightly undulating; shell thickness ranging from 0.15 to 0.25 mm; pore openings elliptical or teardrop-shaped, ranging from 30 to 80 μm in diameter; and shell units wider than higher, with the interstices forming an obtuse triangle. Specimens of Bauruoolithus also show only slight signs of extrinsic degradation that, coupled with the evidence that some of them constitute hatched eggs, suggests that the egg-laying taxon had a different pattern of egg incubation, in which the hatchling could break through the rather thin eggshell relatively easily and that the extrinsic degradation of the eggshell was not necessary. This contrasts with the pattern of incubation for all other known crocodylomorphs and crocodiloid eggs, where extrinsic degradation is a key component of the hatching process. [ABSTRACT FROM AUTHOR]

The Adamantina and Marilia formations are considered to be the richest vertebrate-bearing units in the Bauru Group, Upper Cretaceous, Brazil. In contrast, the fossil content from the Uberaba Formation, which only outcrops in Minas Gerais State, is scarce and poorly understood. In this essay the first taxonomically informative titanosaur remains unearthed from this unit are reported. They comprise anterior caudal vertebrae from two different individuals corresponding to a probably basal titanosaur (CPP-360) and a derived titanosaur (CPP-217). Although these remains can be clearly distinguished from other titanosaurs on the basis of their unique association of characteristics like the presence of mildly procoelous centra, lateral pits in the anterior caudal vertebrae, and prezygapophyses with a dorsal protuberance in anterior caudals in CPP-360 and the presence of strongly developed prespinal, spinopostzygapophyseal and centropostzygapophyseal laminae in CPP-217, more complete materials are needed to propose them new names. [ABSTRACT FROM AUTHOR]

Material from a new titanosaur from the Bauru Basin (Bauru Group), Brazil is described and compared with well-known titanosaurs. Adamantisaurus mezzalirai gen. et sp. nov. is based on six articulated anterior caudal vertebrae and two haemapophyses collected from the Adamantina Formation, which is considered to be Campanian–Maastrichtian? in age. Adamantisaurus mezzalirai is characterized by the following combination of characteristics: anterior caudal vertebrae with straight or slightly backwardly-projecting neural spines with strongly expanded distal ends, stout prespinal lamina, very wide pre- and postzygapophyseal articular facets, and concave postzygapophyseal articular facets on anterior caudal vertebrae. Although our cladistic analysis has produced equivocal results, Adamantisaurus mezzalirai shares with DGM ‘Series B’ (Peirópolis titanosaur) and Aeolosaurus the presence of postzygapophyses with concave articular facets, and shares with DGM ‘Series B’ the presence of laterally expanded neural spines and stout prespinal lamina. Additionally, A. mezzalirai shares with DGM ‘Series’ C (other titanosaur from Peirópolis) the presence of short neural spines. [ABSTRACT FROM AUTHOR]

The ichthyofauna of the Lower Cretaceous Quiricó Formation (Sanfranciscana Basin), Minas Gerais, Brazil, comprises so far taxa like Hybodontiformes (Chondrichthyes), Dastilbe , Laeliichthys , Mawsonia , and isolated Amiidae teeth and Semionotiformes scales. Here we report new remains of a dipnoan tooth plate and its associated pterygopalatine and Lepisosteidae material comprising isolated scales, a hyoid arch, and a partially preserved individual including several scales, vertebrae, neural and haemal spines, pterygiophores, and associated anal fin. Although isolated or incomplete, these new fossils, collected from upper sandstone levels of fluvio-lacustrine deposits, increase the diversity of the ichthyofauna of the Quiricó Formation. This discovery adds important information to the understanding of the relationships of Brazilian and African faunas during the initial stages of the opening of the Atlantic Ocean. • New Lepisosteidae and dipnoan fossils from the Cretaceous Quiricó Formation, Brazil. • Increase of Lower Cretaceous Lepisosteidae sites in South America. • Quiricó Formation fauna is similar to coeval North African ones. [ABSTRACT FROM AUTHOR]

A dearth of Mesozoic-aged, three-dimensional fossils hinders understanding of the origin of the distinctive skull and brain of modern (crown) birds 1 . Here we report Navaornis hestiae gen. et sp. nov., an exquisitely preserved fossil species from the Late Cretaceous of Brazil. The skull of Navaornis is toothless and large-eyed, with a vaulted cranium closely resembling the condition in crown birds; however, phylogenetic analyses recover Navaornis in Enantiornithes, a highly diverse clade of Mesozoic stem birds. Despite an overall geometry quantitatively indistinguishable from crown birds, the skull of Navaornis retains numerous plesiomorphies including a maxilla-dominated rostrum, an akinetic palate, a diapsid temporal configuration, a small cerebellum and a weakly expanded telencephalon. These archaic neurocranial traits are combined with a crown bird-like degree of brain flexion and a bony labyrinth comparable in shape to those of many crown birds but substantially larger. Altogether, the emergent cranial geometry of Navaornis shows an unprecedented degree of similarity between crown birds and enantiornithines, groups last sharing a common ancestor more than 130 million years ago 2 . Navaornis provides long-sought insight into the detailed cranial and endocranial morphology of stem birds phylogenetically crownward of Archaeopteryx, clarifying the pattern and timing by which the distinctive neuroanatomy of living birds was assembled., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)