Angolatitan

Angolatitan
Temporal occurrence
Upper Cretaceous (Upper Turonium )
91.4 to 89.7 million years
Locations
Bengo Province , Angola ( Itombe Formation )
Systematics
Lizard dinosaur (Saurischia) Sauropods (Sauropoda) Neosauropoda Macronaria Titanosauriformes Angolatitan
Scientific name
Angolatitan
Mateus et al. 2011
Art
Angolatitan Adamastor

Angolatitan is a genus of sauropod dinosaur from the Upper Cretaceous Africa. It is the firstdinosaur discoveredin Angola . The Upper Cretaceous of the southern land masses wasdominatedby sauropods from the Titanosauria group at the time of the Upper Cretaceous. As a relic form of its time, Angolatitan did not belong to the Titanosauria, but is in the family tree of the sauropods as the original Somphospondyli at the base of the line of development leading to the Titanosauria. The genus wasscientifically described in 2011 with the only species Angolatitan adamastor .

features

The only find so far consists of a fragmentary right front limb; The scapula, humerus, ulna and radius as well as the metacarpal bones I, III and IV have survived . The fossils are archived in the Museu de Geologia da Universidade Agostinho Neto in Luanda under the field number MGUAN-PA-003.

The humerus measures 110 cm, the cubit 69 cm in length. The front extremity was overall less robust than most representatives of the Titanosauria. The metacarpal bones were slender and corresponded in length; in the case of the titanosaurs, on the other hand, they were more robust and unequal in length. In contrast to titanosaurs, the ulna lacks a pronounced olecranon , and the metacarpal bone I was not bent.

Systematics

Cladogram , simplified according to Mateus and colleagues, 2011:
Titanosauriformes    Brachiosaurus  Somphospondyli   Angolatitan      Euhelopus  Titanosauria   Malawisaurus      Isisaurus      Saltasaurus      Alamosaurus      Opisthocoelicaudia
Systematic position of Angolatitan

Angolatitan is believed to be more primitive than Euhelopus and the Titanosauria , but more inferred (more advanced) than Brachiosaurus . It is placed at the base of the Somphospondyli , a group that also includes Euhelopus and the Titanosauria . Characteristics derived together ( synapomorphies ) that allow classification within this group can be found on the humerus.

Habitat

The find comes from the Tadi beds, a 50 m thick sediment sequence within the Itombe Formation , which can be dated to the Upper Turon based on the characteristic fish fauna. These are marine deposits, fossils include various ammonites , echinoderms and fish including sharks. Land vertebrates at the site include the tortoise Angolachelys mbaxi , the mosasaurs Angolasaurus bocagei and Tylosaurus iembeensis, as well as various remains of plesiosaurs .

The habitat of Angolatitan is interpreted as desert-like . Presumably, like today's desert-dwelling elephants, this genus was adapted to very dry conditions.

Research history and naming

For a long time, paleontological field work was not possible in Angola, which was shaped by civil war. In 2005, the PaleoAngola project conducted the first paleontological expeditions since the 1960s to explore the fossil-rich Upper Cretaceous of the country. The Angolatitan fossils discovered the paleontologist Octávio Mateus on May 25, 2005 near Iembe in the province of Bengo ; The excavation work took place in May and August 2006.

Angolatitan adamastor was described in 2011 by researchers working with Octávio Mateus. The generic name can be translated as "Angola giant". Adamastor is a mythical sea giant of the South Atlantic feared by Portuguese sailors (Angola was a Portuguese colony until 1975).

Individual evidence

1. ↑ ^{a b c d e f g h i} Octávio Mateus, Louis L. Jacobs, Anne S. Schulp, Michael J. Polcyn, Tatiana S. Tavares, André Buta Neto, Maria Luísa Morais, Miguel T. Antunes: Angolatitan adamastor, a new sauropod dinosaur and the first record from Angola. In: Anais da Academia Brasileira de Ciências. Vol. 83, No. 1, 2011, ISSN  0001-3765 , pp. 221-233, doi : 10.1590 / S0001-37652011000100012 .
2. ^ ^{A b} Rob Cooper: The gentle giant: Scientists discover plant-eating dinosaur that made even the T-Rex look small. In: MailOnline. March 17, 2011, accessed August 11, 2014 .