quarta-feira, fevereiro 08, 2006

Dinosaurs of Portugal

Lourinhanosaurus antunesi Mateus 1998
Theropoda: Eustreptospondilydae
Age: Late Jurassic, 150 Million years
Elements known: holotype has cervical, dorsal and caudal vertebrae, pelvis and hindlimbs. Embryos and eggs are also known.
Bibliography: Mateus, 1998
Distribution: Lourinhã, Portugal
Etymology: Lizard of Lourinhã, dedicated to [Miguel Telles] Antunes.
Size: If complete, the holotype has about 4.5 meters long
Food regime: carnivore
Specimen code: ML370
Comment: The skeleton of Lourinhanosaurus antunesi has 4,5 meters, but it possible that this meet-eater dinosaur reached the 9 meters of length. More than thirty gastroliths (gizzard pebbles that helped to grind food) were found in the ribcage of Lourinhanosaurus. Between them, it was found four claws of small ornithopod dinosaur, its last meal. This case is only direct interaction evidence between two dinosaur species in Portugal and confirms the carnivore regime of Lourinhanosaurus albeit its gastroliths.
Also eggs and embryos of this species are known, being from one of the largest and older dinosaur nests in the world. The study of the Lourinhanosaurus embryo allowed a better knowledge concerning the growth of the dinosaurs. The name is after Lourinhã (Portugal) where was discovered and one of the places most productive for dinosaurs in the Late Jurassic of Europe.

Lourinhasaurus alenquerensis (Lapparent & Zbyszewski 1957)
: Sauropoda
Age: Late Jurassic, 150 Million years
Elements known: a partial skeleton. No skull known.
Bibliography: Lapparent & Zbyszewski 1957
Distribution: Portugal
Etymology: Lizard of Lourinhã and Alenquer
Food regime: herbivore
Comment: This Portuguese sauropod was found in 1946 by an north American geologist working for a an oil company. It was initially described in 1957 as a new species within the genus Apatosaurus, but the classification was difficult. Later, it was reclassified as Camarasaurus and finally in a new genus Lourinhasaurus placed in basal Eusauropoda. Lourinhasaurus is one of the most complete Late Jurassic sauropods in Europe, but it still needs more research on it. The humerus is 150 cm and femur is 174 cm, which shows that it was a very large animal.

Dinheirosaurus lourinhanensis Bonaparte & Mateus 1999
: Sauropoda: Diplodocidae
Age: Late Jurassic, 150 Million years
Elements known: Cervical and dorsal vertebrae
Bibliography: Bonaparte & Mateus 1999
Distribution: Portugal
Etymology: Lizard from [Porto] Dinheiro and Lourinhã
Size: 25 meters long.
Food regime: herbivore
Specimen code: ML414
Comment: Dinheirosaurus is a large sauropod dinosaur of the same family than Diplodocus. From this animal is only known the cervical and dorsal vertebrae plus several ribs, but the palaeontologists can still determine that its body length would reach the 25 meters long. Inside the ribcage were found more than one hundred gastroliths, which are gizzard pebbles, some of them as large as a fist. Dinosaurs and other reptiles did not have any molar teeth and could not chew the plant material; therefore they swallowed stones like birds do nowadays.
Dinheirosaurus, Diplodocus and other diplodocids had long necks and tails. They used their neck to graze a larger area without move whole body and the tail as a whip to defend itself.
Diplodocids and the other sauropods are among the animals with smallest brain regarding to the body size. Such small brain was a great evolutive advantage because it allowed a suitable brain oxygenation while the sauropods raised their heads, stand on the rear feet and eat the high area of the tree canopies.

Dacentrurus Owen 1875
: Thyreophora: Stegosauridae
Age: Late Jurassic, 150 Million years
Elements known: Several incomplete skeletons
Bibliography: Owen 1875 ; Lucas 1902; Lapparent & Zbyszewski, 1957; Antunes & Mateus (2003); Galton (1991)
Distribution: Portugal, France, England, Spain
Etymology: pointed tail, armed
Size: 6-7 meters
Food regime: Herbivore
Specimen code: ML433
Comment: Dacentrurus was first stegosaur dinosaur to be discovered (in 1870). Generally, is believed to have a length of 4-5m, but some specimens demonstrate that would be bigger and probably would be the longest of the all stegosaurs. Instead of having the enormous dorsal plates as in Stegosaurus, the Dacentrurus had smaller plates and longer and sharp thorns in the tail. It is yet to understand if Dacentrurus had scapular spikes, like many others of its family. The specimen in display was dug in Lourinhã, central west Portugal. Dacentrurus is known by a single species, D. armatus.

1 comentário:

Anónimo disse...

Como interpreta os gastrólitos encontrados junto aos ossos de Lourinhanosaurus?