Danuvius

Credit: Velizar Simeonovski.

*Danuvius* is an extinct genus of dryopith hominine that lived in Germany during the Middle-Late Miocene.

## History

The genus was named by Böhme et al. (2019) and named after the Celtic-Roman Danuvius, a river god named after the river Danube, which flows through the region of discovery. The specific epithet is after the archeologist Sigulf Guggenmos, discoverer of the clay pit where the remains were discovered near Pforzen, south Germany. Magnetostratigraphy dating finds an age of 11.62 million years at the Serravallian-Tortonian boundary. The site was excavated between 2015 ad 2018. The holotype is a partial skeleton with crania, vertebrae and long bones, GPIT/MA/10000. Paratypes are an adult left femur, GPIT/MA/10001; an adult femur, big toe and teeth (GPIT/MA/10003); and juvenile teeth with a middle finger (GPIT/MA/10002). This counts to 37 total specimens. They suggest it is a dryopith because of dentition, with the limbs suggesting adaptations toward both suspensory and bipedal locomotion. They found that this combination of traits is completely new for an ape genus, and may have been shared with the human-chimpanzee last common ancestor. They find that obligate quadrupedalism and bipedalism may have arisen from an ancestor bearing both. However, the relations of this genus are still quite unknown, so this cannot be confirmed.

## Definition

 File:Danuvius cranial restoration.png
 File:Danuvius guggenmosi profile.png
On average, it likely weighed about 23 kilograms (51 pounds). The holotype is an adult male that, using the knee and hip joint sizes, was calculated at 26-37 kilograms (57-83 pounds) in weight with a point estimate of 31 kilograms (68 pounds). The adult specimen -10003 was 14-19 kilograms (31-42 pounds) with a point estimate of 17 kilograms (37 pounds). The adult -10001 16 is calculated at 22 kilograms (35-49 pounds) and a point estimate of 19 kilograms (42 pounds). This makes a size smaller than the siamang but smaller than contemporary apes. *Danuvius* has limb proportions much like a bonobo. Individuals had sex determined using canine size, with males presumed to bear larger canines. Like dryopiths, the molars are wide with a broad length between the two cusps. However, there are 3 premolar roots and the canines are more vertically-oriented, unusual in dryopiths. The chest may have been broad. It is the first Miocene ape to have a diaphragm located in the lower chest, suggesting an extended lower back and a greater number of functional lumbar vertebrae. This may have created lordosis that shifted the mass over the hips and legs, allowing for habitual bipedalism.

## Paleobiology

The robust finger and hypertrophies wrist and elbows suggest a strong grip and load bearing capabilities in the arms. The legs have load-bearing abailities, especially in the hypertrophied knee. The ankle loading was probably limited and the ankle could have moved like a hinge, being most stable when perpendicular to the leg as opposed to the angle of other apes. Its toes were probably capable of strong gripping, unlike modern apes. This would have allowed grasping to thinner trees. This degree of load bearing in all of the limbs was since unknown in any primate, though some of the characters seen in *Danuvius* are found in other taxa, but never all of them at once. The authors gave this locomotion the term "extended limb clambering". In total, it was able to walk along mildly-inclined branches with the floot directly laid upon the surface, using its strong big toe to grasp. The knee was strong and capable of balancing while walking by preventing torques, with the hands providing a similar action during suspension of palm-walking. This mode of movement emphasizes knee extension, suspensory mechanisms and lordosis, possibly being ancestral to obligate bipedalism seen in australopithecines.

## Paleoecology

*Danuvius* lived alongside molluscs, fish and cold-blooded vertebrates. Small mammals such as rodents, rabbits, martens, hamsters and shrews were the dominant fauna. The large fauna includes *Dorcatherium*, *Miotragocerus* and *Aceratherium*. The site is located in the Upper Freshwater Mollasse, Molasse basin. By the Late Miocene, the Paratethys had dried and the Alps had lifted, allowing for wetlands to expand within the basin. This era may have also created a drying trend that is characterized by increased seasonality, turning deciduous forest into lesser-dense woodland. Fruit and leaf production also became cyclical rather than seasonal. This cooling trend may have replaced tropical flora with mid-latitude and alpine assemblages. This great change may have made Europe inhospitable for apes, causing the extinction of this genus.

## References

https://en.wikipedia.org/wiki/Danuvius\_guggenmosi