Secao de Paleontologia

Porto Alegre, Brazil

Secao de Paleontologia

Porto Alegre, Brazil
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Kerber L.,Secao de Paleontologia | Ribeiro A.M.,Secao de Paleontologia | Oliveira E.V.,Federal University of Pernambuco
Alcheringa | Year: 2011

The first caviine rodent referable to Galea Meyen, 1832 is described from the late Pleistocene of southern Brazil based on a left dentary with the p4-m3 series. The specimen derives from the Ponte Velha I locality in the Touro Passo Creek (Touro Passo Formation, upper Pleistocene), western Rio Grande do Sul State. The main characters used to assign this specimen to Galea are: anterior area of horizontal crest at the level of prism I of p4; deep anterior area of masseteric fossa; incisor alveolus on the medial face of the dentary extended up to the level of prism II of m2; and presence of cement in the hypoflexid. Currently, the genus has a disjunct distribution, with a group in Argentina, Bolivia and Peru, and another in northern and northeastern Brazil. The presence of this taxon in Pleistocene deposits of Rio Grande do Sul State, Uruguay and the Argentine Mesopotamian, where there are no extant representatives of the genus, indicates its wider distribution during the late Pleistocene. © 2011 Association of Australasian Palaeontologists.

The genus Cavia includes four species for Brazil, C. aperea (at least two subspecies, C. a. aperea and C. a. pamparum), C. magna, C. intermedia and C. fulgida. Aiming to contribute to the anatomy and to distinction of these species the syncranium (skull and mandible) of C. a. pamparum from Rio Grande do Sul State is described and compared with C. magna from Rio Grande do Sul and Santa Catarina States, C. intermedia from Moleques do Sul island on Santa Catarina's coast, and C. fulgida from Minas Gerais and Paraná States. Cavia aperea skull is lower and longer, with laterally compressed rostrum; marked interorbital constriction; elliptical orbit with broad communication with temporal fossa; broad and depressed infraorbital foramen; longer and lower mandible, with angular process not reflected laterally; dental formula 1I.0C.1P.3M; hypselodont teeth; molariforms formed for two prisms, the anterior laminar and the posterior cordiform. Cavia aperea distinguishes from C. magna by a less developed rostrum and ventral root of zygomatic process of maxilla; infraorbital foramen more depressed; posterior portion of dorsal surface of frontals and parietals less convex laterolaterally; paraoccipital apophysis shorter and more bent anteriorly; superior incisors narrower and generally opistodonts (proodonts in C. magna); external tertiary notch (fte) deeper with a thicker cement; anterior prolongation to fte more developed; and a constriction at the bottom of posterior prolongation. Cavia intermedia is distinguished by a shorter jugal; reduced/absent jugal fossa; more prominent depression in the interorbital region; larger sagittal crest; less marked lateral constriction in basisphenoid; wider magnum foramen; lower supraoccipital; fte less marked and its anterior prolongation little developed; the anterior prism of p4 as large as the posterior; anterior prism of m3 larger than posterior; shallow internal secondary notch in m3. Cavia fulgida differentiates by the smaller dimensions and a deeper fte. However southern Brazil specimens with these characters, but not typical coloration of C. fulgida, should belong to C. aperea. More studies are needed to clarify this issue.

Hsiou A.S.,University of Sao Paulo | De Franca M.A.G.,Federal University of Vale do São Francisco | Ferigolo J.,Secao de Paleontologia
PLoS ONE | Year: 2015

The sphenodontian fossil record in South America is well known from Mesozoic and Paleogene deposits of Argentinean Patagonia, mainly represented by opisthodontians, or taxa closely related to the modern Sphenodon. In contrast, the Brazilian fossil record is restricted to the Caturrita Formation, Late Triassic of Rio Grande do Sul, represented by several specimens of Clevosauridae, including Clevosaurus brasiliensis Bonaparte and Sues, 2006. Traditionally, Clevosauridae includes several Late Triassic to Early Jurassic taxa, such as Polysphenodon, Brachyrhinodon, and Clevosaurus, the latter well-represented by several species. The detailed description of the specimen MCN-PV 2852 allowed the first systematic revision of most Clevosaurus species. Within Clevosauridae, Polysphenodon is the most basal taxon, and an IterPCR analysis revealed Brachrhynodon as a possible Clevosaurus; C. petilus, C. wangi, and C. mcgilli as possibly distinct taxonomic entities; and the South African Clevosaurus sp. is not closely related to C. brasiliensis. These data indicate the need of a deep phylogenetic review of Clevosauridae, in order to discover synapomorphic characters among the diversity of these Triassic/Jurassic sphenodontians. © 2015 Hsiou et al.

Castro M.C.,Museo de la Plata | Ribeiro A.M.,Secao de Paleontologia | Ferigolo J.,Secao de Paleontologia | Langer M.C.,University of Sao Paulo
Journal of Vertebrate Paleontology | Year: 2013

The comparative description of the most complete specimen of Dasypus punctatus (Xenarthra, Cingulata), from southeastern Brazil, reveals that the species differs from other Dasypodini by the numerous foramina it has in both buckler and movable osteoderms, providing the basis for the lectotype designation. This species was historically allocated to Propraopus, but the inclusiveness and monophyly of that genus are uncertain. A new phylogenetic analysis groups D. punctatus with the living species of Dasypus in a monophyletic clade for the genus, also supporting a Propraopus clade composed of P. sulcatus and the type species P. grandis. The palatal anatomy corroborates previously suggested affinities between D. kappleri and D. punctatus. On the contrary, the possible synonymy between P. grandis and P. sulcatus needs further investigation, given that they differed on a single character. As usual in cingulate systematics, characters related to osteoderm ornamentation proved essential to determine the relationships of taxa. However, their use requires careful sampling in order to account for intraspecific variation biases. © 2013 by the Society of Vertebrate Paleontology.

Holanda E.C.,Federal University of Rio Grande do Sul | Ferigolo J.,Secao de Paleontologia | Ribeiro A.M.,Secao de Paleontologia
Journal of Mammalogy | Year: 2011

A new species of Tapirus (Perissodactyla: Tapiridae) is described from the upper Pleistocene of the Rio Madeira Formation in Araras, Nova Mamoré Municipality, Rondonia State, Brazil. Tapirus rondoniensis sp. nov. is represented by a nearly complete skull with a unique combination of characters that differ from those of extant and fossil species of Tapirus described from South America. It is diagnosed mainly by its broad frontals that bear a pneumatization extending to the frontoparietal suture, a high sagittal crest, a weakly molarized P2 lacking a protoloph, and a metaloph that merely reaches the base of the ectoloph. T. rondoniensis sp. nov. is similar in some respects to T. terrestris, but it retains some primitive dental and cranial character states in common with T. pinchaque, such as broad frontals and a weakly molarized P2. © 2011 American Society of Mammalogists.

Lopes R.P.,Federal University of Rio Grande do Sul | Ferigolo J.,Secao de Paleontologia
Revista Brasileira de Paleontologia | Year: 2015

Here are described post mortem modifications (pseudopaleopathologies) in 762 specimens of extinct mammals from three middle to late Pleistocene assemblages (Campanha, Chuí Creek and continental shelf) of the state of Rio Grande do Sul, southern Brazil. These assemblages include mostly large-sized herbivores preserved in fluvial facies, although the assemblage from the shelf consist of remains that were reworked several times by sea-level oscillations. Although some patterns of modification are similar between the assemblages (e.g. post-fossilization plain fractures), others such as the grade of abrasion or weathering varies according to the depositional setting. The scarcity of modifications that could be attributed to predators or scavengers indicate that carnivory was not a major process driving the formation of the assemblages. Most of the fossils from the Campanha are complete, but a relatively high proportion of them exhibits advanced stage of weathering, whereas those from Chuí Creek and the continental shelf are mostly unweathered. Most of the remains from the Campanha and Chuí Creek are unabraded, whereas all fossils from the shelf were subject to abrasion. Few fossils exhibit signs of modification by organisms such as plants and insects. Fossils from the continental shelf have crusts of beach rock, and some specimens from the Campanha and Chuí Creek have crusts of calcium carbonate or iron oxide. Besides the abrasion, the main difference between fossils from the continental and marine assemblages is the dark color and higher mechanical resistance of the latter. This difference is related to post depositional geochemical processes in the marine environment. The chemical composition of fossils from Chuí Creek and continental shelf was qualitatively analyzed using energy dispersive X-ray spectrometry (EDX) and compared with recent bones. The results show the presence in the fossils of several elements not found in recent bones, incorporated through diagenetic processes controlled by specific conditions of each depositional environment. © 2015 by the Sociedade Brasileira de Paleontologia.

Hsiou A.S.,Secao de Paleontologia | Albino A.M.,CONICET
Herpetological Journal | Year: 2010

We report new snake vertebral remains originating from the late Miocene of south western Brazilian Amazonia (Solimões Formation) and the middle-late Miocene of Venezuela (Socorro and Urumaco Formations). The Brazilian material was attributed to Boidae (aff. Epicrates sp. and Waincophis sp.) and to two probably undetermined "Colubridae". The new snake vertebrae from Venezuela are referred to the extant boid Eunectes sp. Known specimens from the middle Miocene of Venezuela (Socorro Formation) are re-evaluated as cf. Eunectes. Until now, South American late Miocene squamate records have been reported only from Argentina and Venezuela. We present the first record in the Neogene of Brazil, considerably increasing our knowledge of the South American herpetofauna.

Hsiou A.S.,Secao de Paleontologia | Albino A.M.,CONICET | Ferigolo J.,Secao de Paleontologia
Acta Palaeontologica Polonica | Year: 2010

A redescription of the extinct snake genus Colombophis is presented, on the basis of new specimens from the late Miocene of southwestern Brazilian Amazonia, and those previously reported for the middle Miocene of Colombia and Venezuela. The reappraisal of Colombophis allows the recognition of a new species, C. spinosus sp. nov. The revised diagnosis of the genus is based on the midtrunk vertebrae, distinct from those of other snakes mainly in the features of the neural arch, position and shape of the neural spine, inclination of the zygapophyses, shape of the centrum, and development of the haemal keel. The affinities of Colombophis with "Anilioidea" are still unresolved; it is distinguished from all known extinct and extant "anilioids" due to its great vertebral size and the frequent presence of paracotylar foramina. The posterior paired apophyses of the haemal keel in some vertebrae, and the high neural spine of C. spinosus also contrast significantly with the "anilioid" genera, making the allocation of the genus into this probably paraphyletic group not well supported. Here, we recognized Colombophis as a basal alethinophidian of uncertain relationships.

Hsiou A.S.,Secao de Paleontologia | Albino A.M.,University of the Sea
Alcheringa | Year: 2011

We describe an incomplete trunk vertebra of a snake attributable to the Viperidae, collected from a conglomerate facies in upper Pleistocene sediments at the Mississippi locality, Upper Juruá River, southwestern Brazilian Amazonia. It represents the first fossil snake record from the Pleistocene of this region. This specimen extends the fossil distribution of the Viperidae, representing the northernmost record of a snake in the Brazilian Pleistocene. © 2011 Association of Australasian Palaeontologists.

Kerber L.,Secao de Paleontologia | Ribeiro A.M.,Secao de Paleontologia
Neues Jahrbuch fur Geologie und Palaontologie - Abhandlungen | Year: 2011

The Hydrochoeridae are caviomorph rodents of medium to large size. They are euhypsodont and elasmodont, with a peramorphic trend to increase the number of M3 prisms from basal to advanced taxa. The diversity of this family was higher during the Miocene/Pliocene, but today they are represented by a single genus, with two species, Hydrochoerus hydrochaeris (LINNAEUS, 1766) and H. isthmius GOLDMAN, 1912. In this paper we described fossil remains assigned to H. hydrochaeris from Touro Passo Creek (Touro Passo Formation, upper Pleistocene, Lujanian Age) in western Rio Grande do Sul State, southern Brazil. The main characters used to assign these specimens to H. hydrochaeris are: M3 with 13 free prisms, upper diastema shorter than the maxillary cheek teeth, rostral area relatively wide, smaller proportions than Neochoerus HAY, 1926 and larger than H. isthmius. The presence of H. hydrochaeris suggests that in late Pleistocene of western Rio Grande do Sul State, probably existed environments with permanent water bodies. © 2011 E. Schweizerbartsche Verlagsbuchhandlung, Stuttgart, Germany.

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