Volkheimeria

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Volkheimeria
Temporal occurrence
Middle Jurassic ( Callovium )
166.1 to 163.5 million years
Locations
Systematics
Dinosaur (dinosauria)
Lizard dinosaur (Saurischia)
Sauropodomorpha
Sauropods (Sauropoda)
Volkheimeria
Scientific name
Volkheimeria
Bonaparte , 1979
Art
  • Volkheimeria chubutensis

Volkheimeria is a genus of dinosaurs from the group of sauropods . So far only a single, very fragmentary skeleton is known from the Central Jurassic ( Callovian ) in the Argentine province of Chubut . It is an original representative of the sauropods, the relationships within this group are uncertain. The only species is Volkheimeria chubutensis .

Find and naming

The only skeleton comes from a site near the village of Cerro Cóndor from the layers of the Cañadón-Asfalto formation . Although known since 1949, the numerous fossils from this site were only recovered in 1977, 1982 and 1983 by research teams under the direction of paleontologist José Bonaparte . In addition to the Volkheimeria skeleton, the site also contained five incomplete skeletons of the sauropod Patagosaurus and two skeletons of the theropod Piatnitzkysaurus .

The skeleton consists of some cervical, back and sacral vertebrae, the pelvis, as well as the thigh bone and the shin bone. It was scientifically described for the first time in 1979 by José Bonaparte as a new species and genus, Volkheimeria chubutensis . The generic name honors the Argentine geologist and paleontologist Wolfgang Volkheimer , while the second part of the species name, chubutensis , refers to the province of Chubut .

Features and systematics

The only specimen of Volkheimeria was smaller than the contemporary and much better known Patagosaurus , which could reach a length of up to 14 meters: The iliac bone in Volkheimeria measures 45 centimeters in length, while in Patagosaurus it measures 95 centimeters in length.

In his first description, José Bonaparte classified this genus as the original sauropod from the group of " Cetiosauridae ". John McIntosh (1990) notes that Volkheimeria shows similarities with the Lapparentosaurus from the Central Jurassic Madagascar and represents both genera to the Brachiosauridae . Upchurch and colleagues (2004) meanwhile note that no characteristics are known that support a classification within the Brachiosauridae and that Volkheimeria has not been considered in any phylogenetic study - these authors consequently classify the genus as Sauropoda incertae sedis (sauropod with unknown relationships) . Fernando Novas (2009) argues that Volkheimeria can be classified within the Eusauropoda - a group that includes all sauropods but some very primitive forms. Like other Eusauropods show Volkheimeria opisthocoele - that is, on the front convex and on the back concave - caudal vertebrae; In addition, the anterior trochanter of the femur is absent , while the cnemial ridge of the tibia protrudes to the side. At the same time, Novas notes that this genus shows a number of very original features, some of which are reminiscent of prosauropods ; the shaft of the ischium was slender and the pubic bone elongated, and the spinous processes of the vertebrae were elongated craniocaudally (along the midline of the body). Novas therefore suspects that it was an original representative of the Eusauropoda.

Volkheimeria can be distinguished from other genera by the vertebral hole in the vertebrae, which is cut deep into the vertebral bodies .

Individual evidence

  1. ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , p. 173, online .
  2. ↑ a b c d Fernando E. Novas : The age of dinosaurs in South America. Indiana University Press, Bloomington IN 2009, ISBN 978-0-253-35289-7 , p. 103.
  3. ↑ José F. Bonaparte : Les dinosaures (Carnosaures, Allosauridés, Sauropodes, Cétosauridés) du Jurassique Moyen de Cerro Cóndor (Chubut, Argentina). In: Annales de Paléontologie. Vol. 72, No. 3, 1986, ISSN  0003-4142 , pp. 247-289.
  4. ↑ José F. Bonaparte: Dinosaurs: A Jurassic Assemblage from Patagonia. In: Science . Vol. 205, No. 4413, 1979, pp. 1377-1379, doi : 10.1126 / science.205.4413.1377 .
  5. ↑ Ben Creisler: Dinosauria Translation and Pronunciation Guide. Archived from the original on February 20, 2010 ; Retrieved June 12, 2012 .
  6. ^ John S. McIntosh: Sauropoda. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06726-6 , pp. 345-401, here p. 383.
  7. ^ A b 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. 2004, ISBN 0-520-24209-2 , pp. 259-324, here p. 299