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131.
The knowledge on the Brazilian theropod fauna is hampered by the limited number of specimens unearthed so far. The most potential deposits for the finding of those dinosaurs are the layers of Bauru Group, which comprises several different formations of Late Cretaceous age. Most of those remains are referred to Abelisauroidea, a clade that is particularly well represented in Gondwana. Here we report two new abelisaurid specimens comprising a left ilium (DGM 927-R) and the distal articulation of a right femur (MCT 1857-R) unearthed from the outcrops of Adamantina Formation (Turonian – Maastrichtian) in the locality known as Santo Anastácio, that comprises an abandoned quarry located in the outskirts of the homonymous city in São Paulo State. The ilium has a preacetabular process horizontally oriented and ventrally deflected, as well as an acute angle between this process and the pubic peduncle. The femur shows a well-developed anteromedial crest, but not to the same degree as in noasaurids, and ossified ridges between condyles and tibiofibular crest. Those features allow us to assign both specimens to Abelisauridae. CT-scans of those specimens shows that the ilium has pneumaticities similar to the camellate pattern previously recorded in neosauropods and reveals the diverticula invasion of abdominal air-sacs. The femur presents a developed anisotropic trabecular system, which suggests that the main muscular strain is located at the distal portion of this bone. These features have not been previously reported in Abelisauridae, indicating that the internal organization of the postcranial skeleton in the group is rather complex and quite variable. 相似文献
132.
Here we report the first 2obaichthyid gar from the Lower Cretaceous (Aptian) Codó Formation of the Parnaíba Basin, Northeastern Brazil. It shows the following obaichthyid characters: numerous odontods firmly attached to the outer surface of the dermal bones, free and mobile maxilla, presence of interopercle, lack of contact between the metapterygoid and ectopterygoid, absence of lacrimomaxillary bones, and a prominent spine at the posterior margin of the scales. Due to the presence of scales bearing a prominent ventral posterior spine and a number of additional posterior marginal spines, the fish from the Codó Formation is noticeably the same species found in the Albian Santana Formation of the Araripe Basin, Dentilepisosteus laevis. Although probably restricted to fresh or brackish water, the new discovery adds one more taxon to the assemblages found in the Parnaíba and the Araripe basins. The new record extends the temporal range of this species down into the Aptian (about ∼10 myr older than the previous occurrence). 相似文献
133.
The presence of volcaniclastic rocks related to the silicic magmatism within the Serra Geral Formation has been a matter of long-standing debate. In this paper, we present extensive documentation that supports the presence and abundance of these rocks in the Jacuí Group, a newly discovered volcaniclastic and epiclastic accumulation in southern Brazil. The Jacuí Group is composed of two interfingered stratigraphic units, the Volta Alegre and Tupanciretã formations, and it represents the uppermost stratigraphic unit of the Paraná Basin. The Volta Alegre Formation is primarily composed of resedimented volcaniclastic tuffites, the pyroclasts which were sourced from the Santa Maria subgroup of the Palmas-type of the Serra Geral Formation. The Tupanciretã Formation is composed of fluvial and aeolian deposits transported towards the north–northwest. Deposition of the Jacuí Group began in the Early Cretaceous (∼132 Ma) and was coeval with the acidic volcanism of the Santa Maria subgroup. This group was deposited in a probable interior sag basin that represents either the beginning of the extension in the inner part of the continent that subsequently migrated to the east or the far-field impact of extensional processes that preceded the break-up of Gondwana and the opening of the South Atlantic Ocean. 相似文献
134.
Makarkinia kerneri sp. nov. is described from the Lower Cretaceous Crato Formation of Brazil, based on an incomplete but very well-preserved hind wing (Neuroptera: Kalligrammatidae). The previously presumed attribution of the genus is confirmed, based on the diagnostic characters of its wing venation (e.g., dense crossvenation; the anteriorly directed branches of MP) and the presence of a distinct eye-spot on the wing. Makarkinia is the only American representative and youngest known genus of Kalligrammatidae. With an estimated wing length of 100–160 mm, it has the largest wings amongst all fossil and extant Neuroptera. 相似文献
135.
Two new species, Cretohypna puncta sp. nov. and Cretohypna robusta sp. nov., of Glaphyridae are described and illustrated. These fossils were collected from the Jehol Biota, Lower Cretaceous Yixian Formation of Liutiaogou Village in Ningcheng, Inner Mongolia, China. Up to date, 18 fossil species in 6 genera of Glaphyridae have been reported, among which ten species are from China. Respective keys to the Mesozoic genera of Glaphyridae and to species of Cretohypna Yan, Nikolajev & Ren, 2012 are provided. This is the first report of spiracles in fossil Glaphyridae leading to a hypothesis that the character of the 7th abdominal spiracles present in pleural membrane is a plesiomorphy for Glaphyridae. 相似文献
136.
Cretaceous dinosaur tracks from Hunan Province are historically significant as the basis for three ichnotaxa: Xiangxipus chenxiensis, Xiangxipus youngi, and Hunanpus jiuquwanensis all representing theropodan tracks, described from a single site in 1982. Although the type locality has since been destroyed, the type specimen and replicas remained available for restudy in 2006, when paratype Hunanpus tracks and sauropod footprints were described from a second, nearby locality. Material from both localities is here re-described in detail. It is proposed that while Xiangxipus chenxiensis can be regarded as a distinct ichnospecies, probably representing an ornithomimid trackmaker, Xiangxipus youngi cannot be accommodated in the same ichnogenus. We consider it similar to the ichnogenus Wupus from the Lower Cretaceous of Sichuan Province, and therefore of possible avian affinity. We also find no justification for regarding Hunanpus jiuquwanensis as generically distinct from the widespread ichnogenus Grallator, and therefore rename it Grallator jiuquwanensis comb. nov. The Hunan track record is generally consistent with the sparse record of theropod skeletal remains in the province, but adds evidence of sauropods that was previously lacking. 相似文献
137.
Mawsoniids are a lineage of extinct fresh/brackish water coelacanth fishes, common in Cretaceous Godwanan deposits of South America, North and West Africa and Madagascar. Here we formally describe mawsoniid remains from the fluvio-lacustrine Missão Velha Formation (Lower Cretaceous) of the Araripe Basin, North-East Brazil. The examples from the Missão Velha Formation are here described as Mawsonia cf. gigas, based mainly on elements of the lower jaw and opercular series. The occurrence of M. cf. gigas in the Missão Velha Formation expands the stratigraphic and geographical ranges of the type species. 相似文献
138.
The Molí del Baró-1 site (north-eastern Iberia) has yielded one of the richest fossil assemblages of the continental upper Maastrichtian from western Europe. It includes abundant plant (charophytes, sporomorphs, angiosperm leaves, seeds and logs), invertebrate (mollusc shells, partial insect exoskeletons and eggs) and vertebrate (teeth, bones, eggshells) fossils. The fossil assemblage is composed of both parautochthonous and allochthonous remains that mostly deposited in a pool formed at the edge of a meandering river. Plant megafossil evidence suggest that at least three angiosperm species (a willow-like dicot, palms and a likely typhacean monocot) formed the plant community growing in this fluvial environment. Tooth remains indicate that crocodylomorphs were diverse (including atoposaurids, ziphosuchians and eusuchians) which together with small theropod dinosaurs likely consumed prey carcasses or scavenged near the depositional setting. Prismatoolithid eggshells also suggest the presence of nearby nesting area of theropods. On the other hand, hadrosauroids apparently dominated phytophagous faunas including lambeosaurines as well as more basal forms. The taxonomic composition of the Molí del Baró-1 site matches the expected for the timespan and environment and represents a relevant locality to know the diversity of the latest Cretaceous terrestrial ecosystems in south western Europe. 相似文献
139.
Specimens of the Venicoridae (Heteroptera) occur in the Lower Cretaceous Yixian Formation in northeastern China. We describe a new genus and two new species Halonatusivena shii gen. et sp. nov. and Halonatusivena nervosus sp. nov. from this formation. The veins of the membrane are distinctive; the edges of veins are not simple but resemble an irregular stain, with a reduced vasiform structure previously unknown in the Heteroptera. Remarkably, the antennae of one of the specimens of Halonatusivena shii exhibit morphological abnormality. An identification key for the known species of the Venicoridae is provided. 相似文献
140.