Conferência: a biodiversidade ainda estará viva?

Hoje, às 15h, na Sala Polivalente do Museu Municipal Leonel Trindade, Torres Vedras, porque a Biodiversidade é um tema que nos toca a todos.

Macronários basais e os répteis peri-Atlântic0s no III CJIG, Estremoz.

Malafaia et al., 2010

Hoje, dia 6 de Outubro, serão apresentados na secção de Paleontologia do III Congresso Jovens Investigadores em Geociência, duas comunicações sobre os dinossáurios de Portugal com a assinatura dos investigadores da Sociedade de História Natural. Este congresso está a ser realizado no Centro de Ciência Viva de Estremoz, tendo tido início no dia 4 de outobro. 

“New insights for basal macronarians of Portuguese Upper Jurassic” será apresentada pelo paleontólogo português Pedro Mocho (Universidad Autónoma de Madrid/Sociedade de História Natural), e enfocar-se-á no registo fóssil dos macronários basais do Jurássico Superior, e o seu significado paleobiogeográfico. 

Escasso et al., 2007

“Paleobiogeografia dos répteis peri-Atlânticos do Jurássico Superior português: resposta a padrões de vicariância ou dispersão?” terá início às 17:15 pelo paleontólogo Francisco Ortega (Universidade de Nacional de Educación à Distancia/Sociedade de História Natural) como orador convidado. Os vertebrados fósseis do Jurássico Superior da Bacia Lusitânica serão o enfoque desta conferência, onde será apresentada nova informação sobre os dinossáurios portugueses. Este estudo é mais um contributo pela parte da equipe multi-institucional, com destaque para a Sociedade de História Natural de Torres Vedras, Grupo de Biología Evolutiva de la UNED, Universidad Autónoma de Madrid, Universidad Complutense de Madrid, Centro de Geologia da FCUL e Museu Nacional de História Natural e da Ciência.

Centro de Ciência Viva de Estremoz

Próxima conferência no âmbito do 15º aniversário da Sociedade de História Natural

"Ver para ser visto, mostrar para esconder: como a arte rupestre actuou na nossa evolução" 

- Prof. Luiz Oostebeek (Instituto Politécnico de Tomar)

Dia 2 de Outubro, 15H na sala polivalente do Museu Municipal de Torres Vedras

Os participantes terão entrada gratuita na exposição "Dinossauros que viveram na nossa terra"

Objectos perdidos e encontrados de Suchosaurus girardi nas VI Jornadas de Salas de los Infantes

Os paleontólogos Francisco Ortega e Elisabete Malafaia   

As colecções científicas dos grandes museus de historia natural nunca deixam indiferente a ninguém. Procurando no baú de recordações do Museu Nacional de História Natural e da Ciência (MUHNAC) de Lisboa encontrámos um "objecto" perdido no século passado, parte do holótipo de Suchosaurus girardi (Sauvage, 1897-98). Esta descoberta museográfica foi apresentada pela paleontóloga portuguesa Elisabete Malafaia, investigadora da Sociedade de História Natural de Torres Vedras, em formato póster nas VI Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno em Salas de los Infantes (Burgos). Aquí os deixamos o resumo:

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The species of crocodile Suchosaurus girardi (Sauvage, 1897-98) was based on two jaw fragments with teeth and an isolated tooth collected at the locality of Boca do Chapim (Sesimbra, Portugal). The specimen was later reinterpreted and referred to the spinosaurid dinosaur Baryonyx. This last work was based on the redescription of the jaw fragments (MG324, which includes the two fragments reported by Sauvage, 1897-98 and a third unpublished jaw fragment) deposited on the collections of the Museu Geológico (Lisbon) but the isolated tooth could not be located by the author and was considered lost. However, during recent researches on the collections of paleontology of the Museu Nacional de História Natural e da Ciência (MUHNAC) we found this tooth (MNHN/UL.I.F2.176) among some of the material that was rescued of the fire that destroyed much of the museum on 1978. There are also other specimens from the same locality, such as a tooth assigned to the theropod Megalosaurus aff. superbus beside some labels of material that we have not been able to locate so far. These fossils were collected by P. Choffat during their researches for the service of the Direcção dos Trabalhos Geológicos de Portugal (Direction of Geological Works of Portugal). The geological surveys carried by the DGT (later named Serviços Geológicos) as well as the study of the thousands of geological and paleontological samples collected during these works were apparently developed in collaboration with researches of the MUHNAC. The Boca do Chapim locality is one of the few sources of Early Cretaceous tetrapod remains from the Lusitanian Basin. The fossils described by Sauvage come from sediments of the Papo Seco Formation, which is considered early Barremian in age. The vertebrate assemblage known at the moment from this locality consists of remains identified to fishes, chelonians and dinosaurs, including ornithopods, sauropods and theropods. The specimen herein referred corresponds to a tooth crown without its apex. It measures 30mm on maximum length from the most apical end to the base. The crown presents a conical outline, only weakly labiolingually compressed, and with a slightly recurved distal end. The specimen is well preserved but on one face all the enamel surface is missing. On the surface that preserves the enamel it is possible to verify the presence of at least 5 vertical ridges. These well-define parallel flutes extend along the entire preserved surface from the apical tip to the base. Beside these ridges the enamel presents also a particular ornamentation consisting on a series of thin crenulations, which gives a rough aspect to the crown. The distal carina is missing due to fracture and the mesial one is almost entirely covered with sediment so the presence of denticles could not be verified. The cross-section at the base of the crown is oval in outline, with the long axis mediodistally oriented; it measures 14mm on mediodistal length and 9mm on labiolingual width. The material previously assigned to Suchosaurus girardi by Sauvage was reinterpreted as Baryonyx based on the recognition of a combination of characters share with Baryonyx walkeri from the Barremian of England. The specimen MNHN/UL.I.F2.176 presents a general morphology very similar to the teeth on the jaw fragments described by Buffetaut and some of the characters considered synapomorphies for baryonychine spinosaurids (e.g. the conical shape of the crown with well-marked vertical ridges and distinctive ornamentation of the enamel). Most of the theropod teeth present crowns very compressed labiolingually and smooth enamel surfaces. Only spinosaurid theropods present enamel ornamentation with well-defined vertical ridges and thin crenulations. The teeth from Boca do Chapim differs from those of Baryonyx walkeri in the presence of ribs on both sides of the crown whereas the teeth of the holotype usually have smooth labial surfaces. Other baryonychine teeth from England present ridges on both lingual and labial surfaces; and this morphology is also present on some teeth from Spain. The specimens from Boca do Chapim are also similar to some teeth from the Late Jurassic of Tendaguru Formation (Tanzania) on the presence of several longitudinal ridges on both sides and a fine wrinkling on the enamel. Based on these characters Buffetaut suggested that these teeth might represent an early spinosaurid. Although, the fine wrinkling of the enamel on the Tendaguru specimens is weakly developed unlike the granular texture in the Portuguese specimens and in other baryonychines. More recently, other specimen consisting on cranial and postcranial material from Praia das Aguncheiras, about 15km to the southeast of Boca do Chapim, was also assigned to the species Baryonyx walkeri. This specimen comes from Barremian sediments of the Papo Seco Formation that correspond to the same levels as the fossils described by Sauvage. The record of baryonychine spinosaurids known at the moment suggests that these were common on the theropod assemblages from the Early Cretaceous of Europe. The group is represented on sediments of the Hauterivian, Barremian and Aptian from England, Portugal and Spain. Some authors argued that the presence of baryonychines in the Iberian Peninsula may be of some paleobiogeographic importance to explain the dispersion of this group of dinosaurs between Europe and Africa, which may have taken place via a route thought Iberia.

Mas información:

• Referencia: Malafaia, E.; Ortega, F.; Escaso, F.; Mocho, P. 2013 Rediscovery of a lost portion of the holotype of Suchosaurus girardi (Sauvage, 1897-98), now related to the spinosaurid theropod Baryonyx. In: Torcida Fernández-Baldor, F.; Huerta, P. (Eds.). Abstract book of the VI International Symposium about Dinosaurs Palaeontology and their Environment: 82-84.

Os Dinossários de Portugal no III Congresso de Jovens Investigadores em Geociências, Estremoz

Paleontólogo Francisco Ortega escavando no Cretácico Inferior

No próximo dia 6 de Outubro, às 17:00, Francisco Ortega, investigador da Universidad Nacional de Educación a Distancia (Espanha) e Sociedade de História Natural de Torres Vedras, realizará uma conferência como orador convidado no âmbito do III Congresso de Jovens Investigadores em Geociências a realizar no Centro de Ciência Viva de Estremoz.

Intitulada de “Paleobiogeografia dos répteis peri-Antlânticos do Jurássico Superior português: resposta a padrões de vicariância ou dispersão?”, esta palestra propõe uma breve reflexão sobre os vertebrados fósseis do Jurássico Superior Português, na qual ainda haverá espaço para a apresentação de nova informação sobre alguns dos grupos de vertebrados em estudo.

Esta comunicação surge como resultado da investigação levada a cabo sobre as faunas de vertebrados mesozóicos da Bacia Lusitânica por parte de diversos investigadores associados tanto a instituições nacionais como internacionais, destacando-se o Grupo de Biologia Evolutiva da UNED, Sociedade de História Natural de Torres Vedras, Universidad Autónoma de Madrid, Universidad Complutense de Madrid, Centro de Geologia da Faculdade de Ciências da Universidade de Lisboa e o Museu Nacional de História Natural e da Ciência.

Escavação de Porto Dinheiro, com o paleontólogo português Pedro Dantas (SHN) na foto. 

Spinophorosaurus nas VI Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, Salas de los Infantes

Pedro Mocho, investigador da Sociedade de História Natural, em plena apresentação de Spinophorosaurus

A Sociedade de História Natural de Torres Vedras apresentou-se mais uma vez nas VI Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno de Salas de los Infantes (Burgos). Um dos trabalhos apresentados foi conduzido por investigadores da SHN, Pedro Mocho, Francisco Ortega e Fernando Escasso. Este trabalho contou também com o contributo de Ainara Aberasturi, investigadora do Museo Paleontológico de Elche (MUPE). A Universidade Autónoma de Madrid e o Grupo de Biología Evolutiva da UNED foram outras instituições implicadas neste estudo. 

O trabalho apresentado pretendia expor nova informação relativa a Spinophorosaurus nigerensis, um saurópode encontrado no Jurássico Médio do Niger, e um dos especímenes mais bem conservados do registo fóssil a nível mundial. O facto de ser datado do Jurássico Médio e de corresponder ao um eusaurópode basal (um grupo de saurópodes primitivos e diverso ao longo deste período), faz de Spinophorosaurus uma das mais importantes chaves para a compreensão deste grupo e da sua evolução.

Deixamos aqui o resumo deste trabalho:

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Spinophorosaurus (Sauropoda), a new look inside eusauropod evolution

The sauropod Spinophorosaurus nigerensis was established by Remes et al. (2009) from two individuals found in sediments of Middle Jurassic of Niger and was firstly considered as a non-eusauropod sauropod. Nevertheless, those authors noted several similarities between Spinophorosaurus and some Eurasian Middle Jurassic forms, such as Shunosaurus and mamenchisaurids. Spinophorosaurus is one of the most complete basal sauropods known to date, and its phylogenetic reassessment might add important information about the early phase of eusauropod evolution and Middle Jurassic eusauropod paleobiogeography. In fact, the reassessment of the Spinophorosaurus holotype, with the availability of previous unprepared elements, is providing valuable new information about its anatomy and new data for the morphological data matrices. Spinophorosaurus was firstly considered as a sister taxon of eusauropods (Remes et al., 2009), more primitive than Shunosaurus and some Middle Jurassic Gondwanic sauropods, such Barapasaurus and Patagosaurus. Spinophorosaurus bears some primitive traits such as the absence of quadrate fossa, denticles in both tooth carinae, such as Barapasaurus, and the absence of spinodiapophyseal lamina in middle and posterior dorsal vertebrae. However, several apomorphic features within eusauropods are identified in Spinophorosaurus such as the presence of five sacral vertebrae, distally expanded dorsal neural spines or a reduced ischiatic peduncle, and the presence of “forked” chevrons with a cranial and a caudal pronounced process (Wilson, 2002; Upchurch et al., 2004). Spinophorosaurus also is particular similar with the eusauropods Mamenchisaurus or Omeisaurus. In this sense, the most surprising feature of Spinophorosaurus is the presence of camellate bone in dorsal vertebrae. This type of bone is common in titanosauriforms, but it was convergently acquired by mamenchisaurids such as Mamenchisaurus and Omeisaurus (Wedel, 2003; Mannion et al., 2013). Spinophorosaurus lacks some of the typical characters of Neosauropoda sauropods, such as dorsally bifurcated centroprezygapophyseal lamina on the dorsal vertebrae, circular proximal section of the tibia, and presence of pleurocoels in the sacral vertebrae (Wilson, 2002; Upchurch et al., 2004), so it is considered to be out of this group. This fact is congruent with the phylogenetic scenario during the Middle Jurassic. The reassessment of Spinophorosaurus provides a new codification for Wilson (2002) and Upchurch et al. (2004) data matrices. Results of maximum parsimony analyses consider Spinophorosaurus as a eusauropod, more derived than Shunosaurus and Barapasaurus, and close related with Patagosaurus and the mamenchisaurids Mamenchisaurus and Omeisaurus. Further phylogenetic approaches can provide new perspectives for understanding the evolution of several morphological traits, such as the camellate tissue in eusauropods, and to reformulate the paleobiogeographical model previously proposed.

Más información: 

• Mocho, P.; Ortega, F.; Aberasturi, A.; Escaso, F. 2013 Spinophorosaurus (Sauropoda), a new look inside eusauropod evolution. In: Torcida Fernández-Baldor, F.; Huerta, P. (Eds.). Abstract book of the VI International