Paralititan
| Paralititan | ||||||||||||
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Paralititan stromeri (living reconstruction ) |
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| Temporal occurrence | ||||||||||||
| Upper Cretaceous ( Cenomanium ) | ||||||||||||
| 100.5 to 93.9 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Paralititan | ||||||||||||
| Smith et al. , 2001 | ||||||||||||
| Art | ||||||||||||
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Paralititan was a genus of sauropod dinosaurs from the Titanosauria group thatlived inwhat is now Egypt during the early Upper Cretaceous ( Cenomanium ).
It is only known from a partial skeleton, which was discovered in the Bahariyya oasis in 2000 and in 2001 by Smith et al. has been described. The only known species ( type species ) of this genus is P. stromeri . Paralititan may have lived in a mangrove forest-like ecosystem and is the first dinosaur to be identified from this ecosystem.
Naming
The generic name Paralititan is made up of the Greek words paralos = "near the sea" (from παρα, para = "near", "next to" and ἅλς, háls = "salt", "sea") and titan . The Artepitheth stromeri honors the German paleontologist Ernst Stromer von Reichenbach , who carried out research in the Bahariyya Oasis in the early 1900s and found, among other things, the remains of four previously unknown species of dinosaur.
Find and habitat
The partial skeleton ( holotype CGM 81119) consists of several vertebrae, elements of the shoulder girdle and the forelegs: two fused pelvic vertebrae, the first and another anterior caudal vertebra, ribs, an incomplete shoulder blade (scapula), the left and right humerus (humerus), a metacarpal bone and some other elements. A vertebra (1912VIII64) described by Stromer could also have belonged to Paralititan , but has been lost.
From a geological point of view, the find comes from the Bahariya Formation and is thus attributed to the early Upper Cretaceous ( Cenomanium ). The low-energy sediments at the site suggest a mudflat, as the bones were once in the intertidal zone.
Some of the plant material found belonged to Weichselia reticulata , a fossil tree fern that is counted among the mangrove trees . Furthermore, plant roots were found in situ , which run through the bone-bearing layer and indicate a limited water depth. The researchers assume that the animal visited the mangrove before it died - it is unlikely that the bones were washed up to this place, as they were very close together and the flat, overgrown mudflats would have prevented transport.
A tooth of the theropod cf. Carcharodontosaurus was found in the bones, which suggests that scavengers have eaten the carcass. The possibility that the tooth was washed to the locality is also unlikely here due to the size of the tooth of 65 mm.
Description and system
Paralititan is one of the bulkiest sauropods ever found. The humerus , which is clearly elongated at both ends, measures 1.69 meters in length, making it the longest known from a Cretaceous sauropod.
Due to the scarce bone material, more precise information on the size remains speculative. However, comparisons with other titanosaurs show that Paralititan was perhaps smaller than the giant Argentinosaurus , whose humerus was not found but is estimated to be 1.81 meters long. Carpenter (2006) gives the length of Paralititan at 26 meters, the calculation was based on the physique of the better known Saltasaurus . The weight of Paralititan is estimated by Burness and colleagues (2001) at 69 tons.
The first descriptors classified Paralititan within the family Titanosauridae , as there are some similarities with other titanosaurids. The posterior pelvic vertebrae have no cavities, but the caudal vertebra found is strongly procoelic (concave on the front) and has a well-developed distal condyle (posterior articular knot). In addition, the metacarpal bone was flattened at the distal (lower) end - which suggests that the finger bones were either significantly reduced or missing. However, the internal systematics of the Titanosauria is highly controversial. Many newer authors consider the Titanosauridae to be invalid, which is why they often no longer appear in more recent cladistic analyzes. Instead, Paralititan is classified within the group of Lithostrotia.
Other features have been described as autapomorphies (unique features) and distinguish Paralititan from other genera. These features include processes on the shoulder blade and humerus, the shape of the caudal vertebra (wider than high), and the rectangular shape of the radial condyle (the articular knot that connects the humerus to the radius , the spoke, in the elbow joint ). These features also allow a clear differentiation from Aegyptosaurus , another sauropod from the Bahariyya oasis, which was described by Stromer, but whose remains have been lost. Aegyptosaurus , whose humerus was 59% smaller than that of Paralititan , cannot currently be classified more precisely and is considered incertae sedis within the Titanosauria .
Paleofauna and meaning
Ernst Stromer carried out research in the Bahariyya oasis in the early 20th century and described a diverse fauna: the vertebrates described include fish , turtles , scallops , crocodiles , plesiosaurs and dinosaurs. Very large vertebrates include the 3.5 meter long coelacanth Mawsonia and the 10 meter long crocodile Stomatosuchus ; but also the large theropods Spinosaurus , Carcharodontosaurus and Bahariasaurus . However, a large part of Stromer's collection was destroyed in an Allied bombing raid on Munich in 1944. There were no further finds - Paralititan is the first terrestrial vertebrate described from the Bahariyya oasis since 1935.
The find is significant because dinosaur finds from the late Cretaceous Africa are rare. A better knowledge of this vertebrate fauna also helps to better understand the breakup of the southern continent of Gondwana .
literature
Unless otherwise stated, all information comes from the following scientific publication :
- Joshua B. Smith, Matthew C. Lamanna, Kenneth J. Lacovara, Peter Dodson, Jennifer R. Smith, Jason C. Poole, Robert Giegengack, Yousry Attia: A Giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt. In: Science . Vol. 292, No. 5522, 2001, pp. 1704-1706, doi: 10.1126 / science.1060561 (alternative full text access : ResearchGate ).
Individual evidence
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ u. a. 2010, ISBN 978-0-691-13720-9 , p. 209, online .
- ↑ Kenneth Carpenter : Biggest of the big: a critical re-evaluation of the mega-sauropod Amphicoelias fragillimus Cope, 1878. In: John R. Foster, Spencer G. Lucas (eds.): Paleontology and geology of the Upper Jurassic Morrison formation (= New Mexico Museum of Natural History & Science. Bulletin. 36, ISSN 1524-4156 ). New Mexico Museum of Natural History & Science, Albuquerque NM 2006, pp. 131-138, online .
- ↑ Gary P. Burness, Jared Diamond , Timothy Flannery: Dinosaurs, dragons, and dwarfs: The evolution of maximal body size. In: Proceedings of the National Academy of Sciences of the United States of America . Vol. 98, No. 25, 2001, pp. 14518-14523, doi: 10.1073 / pnas.251548698 .
- ↑ Jeffrey A. Wilson: An Overview of Titanosaur Evolution and Phylogeny. In: Fidel Torcida Fernández-Baldor, Pedro Huerta Hurtado (eds.): Actas de las III Jornadas Internacionales sobre Paleontología de Dinosaurios y Su Entorno. = Proceedings of the 3rd International Symposium about Paleontology of Dinosaurs and their Environment Paleontología de dinosaurios y su entorno. Salas de los Infantes (Burgos, España), 16 al 18 de septiembre de 2004. Colectivo arqueológico-paleontológico de Salas, Salas de los Infantes (Burgos, España) 2006, ISBN 84-8181-227-7 , pp. 169-190 .
- ^ Paul Upchurch , Paul M. Barrett , Peter Dodson : Sauropoda. In: David B. Weishampel , Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. a. 2004, ISBN 0-520-24209-2 , pp. 259-324, here p. 313.
