Telmatosaurus

*Telmatosaurus transylvanicus*

***Telmatosaurus*** (meaning "marsh lizard") is a genus of basal hadrosaurid dinosaur from the Late Cretaceous. It was a relatively small hadrosaur, approximately five meters (16 ft) long, found in what is now Romania. It was smaller than many other hadrosaurs due to insular dwarfism, growing to approximately 5 metres in length. Its name means 'marsh lizard'.

## Description

The relatively small size of *Telmatosaurus* with a length of five metres and a weight of half a tonne, has been explained as an instance of insular dwarfism.

## Discovery

In 1895 some peasants presented Ilona Nopcsa, the daughter of their lord, with a dinosaur skull they had found at the estate Săcele in the district Hunedoara (then named Hunyad) in Transylvania. Ilona had an elder brother, Ferenc or Franz Nopcsa von Felső-Szilvás who was inspired by the find to become a paleontology student at the University of Vienna. In 1899 Nopcsa named the skull *Limnosaurus transsylvanicus*. The generic name was derived from Greek limnè, "swamp", a reference to the presumed swamp-dwelling habits of hadrosaurs. The specific name referred to Transylvania.[1] Later Nopcsa discovered that the name *Limnosaurus* had already been used by Othniel Charles Marsh in 1872 for a crocodilian (later reclassified as *Pristichampsus*), so in 1903 Nopcsa renamed the genus *Telmatosaurus*. Telma again means "marsh". In 1910 Barnum Brown, unaware of Nopcsa's replacement name, named the genus *Hecatasaurus*, but this is a junior objective synonym.

The holotype, BMNH B.3386, was found in the Haţeg Basin in a layer of the Sânpetru Formation dating from the Maastrichtian, about 68 million years old, at the time part of the Haţeg Island, one of the islands of the European Archipelago. It consists of a skull with lower jaws.

In 1915 Nopcsa referred his species to the genus *Orthomerus*, as an *Orthomerus transsylvanicus*. However, since the 1980s, *Orthomerus* has been considered a *nomen dubium*, leading to a revival of the name *Telmatosaurus*. Fragmentary hadrosauroid material from Spain, France and Germany, that had been referred to *Orthomerus*, is now often assigned to *Telmatosaurus*, but an identity is hard to prove; the same is also true of many Romanian fragments and eggs.

## Environment

Hațeg Island was a large island featuring swamp-like environments in western cretaceous Europe, and home to many other dinosaur species such as *Magyarosaurus*, a dwarf sauropod of only six metres. Pterosaurs such as Hatzegopteryx fed on these dwarf dinosaurs, likely including *Telmatosaurus*. *Zalmoxes* was a bipedal ornithopod that accompanied *Telmatosaurus*, and a somewhat symbiotic relationship between the animals may have been present - the *Telmatosaurus* stripping newly evolved flowering plants of their leaves as the *Zalmoxes* ate the fallen fruits from the ground, clearing the ground and feeding themselves.

## Behavior

Like other hadrosaurs, *Telmatosaurus* likely travelled in herds for 'safety in numbers', due to the threats of the top dinosaur predator *Balaur*, a flightless bird. Due to their habitat, they likely fed on broad-leaved trees and horsetails near the water's edge. This means that they were likely prey of crocodiles.

## Paleobiology

### Paleopathology

A juvenile Telmatosaurus examined by Dumbrava et al. bears a large non-cancerous tumor called an ameloblastoma on its lower jaw. The presence of this benign tumor in a dinosaur is a first, as before the discovery, ameloblastomas were known only from modern mammals (including humans) and reptiles. The discovery of an ameloblastoma in a dinosaur gives evidence that the development of benign tumors is a basal characteristic, not just a relatively modern condition.
It is unlikely that the tumor caused the dinosaur any serious pain during its early stages of development, just as in humans with the same condition, but researchers can tell from its size that this particular dinosaur died before it reached adulthood. Since its preserved remains consist of only the two lower jaws, no one can ascertain its cause of death. The researchers were left wondering whether the presence of the ameloblastoma could have contributed to its death. From modern examples, it is well known that predators often target weak or injured individuals of the herd. The tumor in this dinosaur had not developed to its full extent at the moment it died, but it could have indirectly contributed to its early demise.

### Diet

Telmatosaurus dined on C3 plants, shrubs, herbaceous plants, leaves and seeds.

## JPInstitute.com Description

Telmatosaurus is one of only two duck-billed dinosaurs known to have lived in Europe. Although these rather large plant-eaters were the most common dinosaur in North America during the last part of the Cretaceous, fossils of this family have been hard to find in Europe. Telmatosaurus was fairly small compared to other duck-bills; some, such as Edmontosaurus, found in North America and China were three times as big! This small size is due to the fact that Europe in the late Cretaceous was flooded and made up of many islands. Being restricted to islands, animals tend to become smaller, and almost all the dinosaurs found from late Cretaceous Europe are smaller than their relatives in other parts of the world.

Telmatosaurus is considered to be a more primitive member of the hadrosaur family even though it lived during the last part of the Cretaceous. It also seems to support the idea that many of the island dwelling dinosaurs of Europe during that period were subject to dwarfism relative to their larger family members.

## Links

https://web.archive.org/web/20030813040459/http://www.jpinstitute.com/dinopedia/dinocards/dc\_telmatosaurus.html
https://web.archive.org/web/20080706163223/http://kids.yahoo.com/dinosaurs/413--Telmatosaurus