Shingopana

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Shingopana
Temporal occurrence
Albium to the lowest Cenomanium ?
110 to 100 million years
Locations
Systematics
Dinosaur (dinosauria)
Lizard dinosaur (Saurischia)
Sauropodomorpha
Sauropods (Sauropoda)
Titanosaurs (Titanosauria)
Shingopana
Scientific name
Shingopana
Gorscak et al. , 2017

Shingopana is a genus of sauropod dinosaurs from the Titanosauria group . The only known species of the so far monotypical genus is Shingopana songwensis from the Albium / lowest Cenomanium (?) (Approx. 100 to 110 million years ago) of Tanzania.

Etymology and find history

The generic name is made up of the Kiswahili words "shingo" ("neck") and "pana" ("broad") and refers to a characteristic, bulge-like bulge on the spinous processes of the cervical vertebrae. The additional species " songwensis " refers to the Songwe in southwestern Tanzania, in whose area the type species was found. The species name can roughly be translated as “Der Breitnacken vom Songwe”.

As part of the “Rukwa Rift Basin Project” (RRBP), a cooperation between Ohio University (USA), Michigan State University (USA), James Cook University (Australia) and the University of Dar es Salaam (Tanzania), as "TZ-07" identified site first brought up the remains of a sauropod in 2002. The finds were recovered in several excavation campaigns between 2002 and 2004. The first description was in 2017 by Gorscak et al.

Fossil record

All hitherto known remains of Shingopana are from the Namba member of Galula formation in Rukwa- rift basins , a portion of the Central African trench in the southwestern Tanzania. Shingopana thus continues to Rukwatitan already the second representative of the titanosaur from the Namba member of Galula lineup and is likely to have almost lived at the same time with this in the same region.

The holotype (RRBP 02100) represents the largely disarticulated partial skeleton of an individual and comprises several partially preserved cervical vertebrae, six partially preserved cervical ribs and four partially preserved dorsal ribs, an almost complete left humerus , a partially preserved pubic bone and, as the only element of the cranial skeleton, a left one Os angular . The fossil material available to date thus corresponds to around 10% of the total skeleton.

Characteristics of the genus

A characteristic of the middle to posterior cervical vertebrae is a characteristic of the species ( autapomorphy ): A narrow bone ridge (lamina) extends from the anterior articular processes of the vertebrae ( prezygapophyses ) towards the spinous process ( spinous process). This lamina is divided into two parts and, unlike all other representatives of the Titanosauria , includes a trench-shaped indentation (fossa). The branch of the lamina oriented towards the center of the vertebra leads directly to the spinous process of the vertebra. The laterally located branch leads to the eponymous bulges on the spinous process.

Age classification of the find

The Galula Formation comprises terrestrial sediments that were deposited during the “Middle” Cretaceous Period , from the Aptian to the Cenomanian . This roughly corresponds to the period from 126.3 to 93.9 million years ago. The Namba member from which the find originates corresponds to the most hanging parts of the Galula Formation. First attempts at radiometric dating of the Galula Formation itself did not produce satisfactory results, only a poorly defined maximum age of the sediments. Stratigraphic and sedimentological examinations of the sediments of the Namba member provided better results, which showed that the deposits must have occurred almost at the same time or shortly before the activity of a nearby volcanic center. These volcanic rocks could be successfully dated to an age of approx. 99–115 million years. The first writers cautiously give the age of the find at around 100-110 million years, which would roughly correspond to the period from the Albian to the lowest Cenomanian.

Paleecology

The sediments of the Namba Member represent the deposits of an interwoven river system and are predominantly characterized by sandstones. In between, however, there are also larger, lens-shaped bodies of partly fine-sand clay and silt stones, which can be interpreted as deposits in oxbow lakes that are temporarily cut off from the main flow system. The fossil remains of Shingopana songwensis also come from such an area . Paleo soils from the Namba Member indicate an open forest landscape with a tropical, subhumid climate.

All bones of the holotype show signs of weathering, meaning that they were exposed to atmospheric influences for a long period of time before the fossilization. Signs of "trampling" or bite marks from carnivores could not be found. Instead, the bones show a multitude of different drill marks. Some of these traces could be assigned to the Ichnogenus Cubiculum . These traces are probably due to the larvae of scavenging beetles.

Individual evidence

  1. ↑ a b c d e f E. Gorscak, PM O'Connor, EM Roberts & NJ Stevens: The second titanosaurian (Dinosauria: Sauropoda) from the middle Cretaceous Galula Formation, southwestern Tanzania, with remarks on African titanosaurian diversity. In: Journal of Vertebrate Paleontology , e1343250 (22 pages), 2017. (online)
  2. ↑ PM O'Connor, JJW Sertich, NJ Stevens, EM Roberts, MD Gottfried, TL Hieronymus, ZA Jinnah, R. Ridgely, SE Ngasala & J. Temba: The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana. In: Nature , Vol. 466, pp. 748-751, 2010. (Abstract)
  3. ^ EM Roberts, PM O'Connor, NJ Stevens, MD Gottfried, ZA Jinnah, S. Ngasala, AM Choh & RA Armstrong: Sedimentology and depositional environments of the Red Sandstone Group, Rukwa Rift Basin, southwestern Tanzania: New insight into Cretaceous and Paleogene terrestrial ecosystems and tectonics in sub-equatorial Africa. In: Journal of African Earth Sciences , Vol. 57, Issue 3, pp. 179–212 2010. (digitized version )

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