⊛ Procompsognathus

What is a Procompsognathus?

Procomsognathus was a coelophysid dinosaur that lived in the Triassic period, about 210 million years ago in Europe.. It was a small, light, bipedal carnivore that was up to 1 meter long.

Its name is due to the fact that its discoverer Eberhard Fraas confused it with an ancestor of Compsognathus. It is one of the few dinosaurs found in Germany and only a partial fragmented skeleton is available.

It had long legs, short arms and large hands with five fingers. Added to this was a long snout, which had many small teeth. They also had a stiff tail.

It was in fact similar in size to Compsognathus, although it was possibly lighter. It fed on lizards, insects and small mammals.

Procompsognathus discovery

It was named in 1913 by Fraas, and was based on an incomplete skeleton and poor conservation conditions. The fossil of it was found in 1909 in Baden-Württemberg in the vicinity of Pfaffenhufen in the white quarry.

The holotype fossil had three parts. One consisted of a partial skull containing a three-inch-long jaw. The second and third parts included six cervical vertebrae, ten dorsal vertebrae, thirteen caudal vertebrae, some ribs, the shoulder girdle, parts of one front leg, one intestinal bone, two pubic bones and the hind legs..

The second and third parts were probably found together, with a high probability of belonging to an adult individual. Although some believe that the skull did not match, that it could be from another specimen.

The name Procompsognathus means before Compsognathus, which would place him as an ancestor. However, this is not true, since there is no ancestry relationship between both species. The name only remained as an indication that both dinosaurs were small in size.

Because the fossil is in poor condition, it is not difficult to classify Procompsognathus. Even at the time of naming it Eberhard Fraas assumed it was a dinosaur. But then the existence of small archosaurs that were common in the Triassic was unknown.

Therefore, in 1932 Friedrich von Huene stated that Procompsognathus was actually a Psedosuchia. However, postcranial reconstruction does not coincide with this and is an issue that is discussed in the scientific community.

They are generally still considered a theropod. Taking into account its crocodile-like skull and its age, it is thought that it could be a very basal theropod.

John Ostrom conducted a comparative study between Procompsognathus and Compsognathus in 1982 and concluded that they were actually unconnected. Paul Sereno in 1992 believed that the skeleton was from Procompsognathus and that the rest of the material was from a Saltoposuchus connectensa member of Sphenosuchia and therefore a member of Crocodylomorpha.

In 1921 Friedrich von Huene wrote that both skulls could barely be distinguished from Saltoposuchus. In 2004, David Allen claimed that Procompsognathus belonged to Avemetatarsalia. That is to say, it was not a dinosaur. However, this was not supported by a cladistic analysis.

Currently, authors such as Oliver Rauhut and Axel Hungerbuhler consider it to be a dinosaur of the Coelophysoidea family. They were based on the possibility that another fossil could be attributed to this species.

His vertebrae are advanced but his feet and ossa pubis They have primitive characteristics. In 1911 Fraas associated Procompsognathus with the origins of birds, as a small bipedal form.

The site where they found their fossil remains was in the Stubensandstein Formation, which is located in the Lowenstein area of Baden-Württemberg, Germany. This was an alluvial plain with a semi-dry to semi-humid climate. It was part of the Keuper basin in the south of this country.

Albert Burrer’s quarry was on the northern slope of the Stromberg region. That area experienced frequent volcanic eruptions. There a variety of fossils have been found such as those of Efraasia, Plateosaurus, Teratosaurus and Nircrosaurus.

What does Procompsognathus mean?

Name Procompsognathus is based on his supposed descendant Compsognathus. This came from Greek compsos what does it mean elegant, refined or delicate and of gnathos what is jaw.

The prefix pro refers to something that was before or what was ancestor of. The epithet triassicus indicates the geological period it belonged to, which was the Triassic.

Therefore, his name means before elegant jaw.

The Coelophysoidea family

The Coelophysoidea, name that means hollow shapes was a group of carnivorous dinosaurs that lived between the late Triassic and early Jurassic. They enjoyed a great geographic extension and probably lived on all continents.

Also called coelophysis, these were slender, carnivorous animals, similar to the coelurosaurs into which they were first classified. Some had a crest on their heads. They could measure between 1 and 6 meters in length.

They are distinguished by the shape of the maxillary bone, which has a small kink known as subnarial cleft. Hollow bones were characteristic of theropods, which gave rise to their name. They also had long, thin limbs.

Its skull was flat and narrow, and its neck was longer than its body. Her jaws were provided with small sharp teeth. There is no information about what his epidermis was like.. Various artists have portrayed them with reptile skin or even feathers.

Some species live in small groups. This is known from several localities where numerous fossils were discovered together. Its most popular representatives were the Coelophysis, Liliensternus and the Dilophosaurus.

Many were originally named within the group Podokesauridaebut now they are called Coelophysoidea.

Characteristics of Procompsognathus

This small specimen that lived in the Triassic, which despite appearances is not related to the Compsognathus, has been the subject of studies by scientists. Read below to learn more.

Classification

The only fossil found of Procompsognathus triassicus It was difficult to classify taxonomically, due to its profound deterioration. But as a general rule it is considered a theropod. Some specialists consider it as an Ornithodira.

According to Rauhut and Hungebuhuler, the vertebrae can be classified as Coelophysidae or Ceratosauridae according to their analysis from 2000. Carrano and collaborators concluded in 2005 that they belong to the Coleophysidae.

Description

The length of Procompsognathus was around 1 meter. Although Fraas in 1913 estimated that it could measure up to 75 cm. Gregory S. Paul evaluated in 2010 that it could weigh 1 kilogram and that its length was around 1.1 meters.

Six years later, new estimates were made that indicated 1.3 kg in weight and up to 28 centimeters in height..

Procompsognathus possessed long hind legs, short arms, large clawed hands, a long, thin snout, and many small teeth.

The exposed femur of the specimen measures 93 mm and its tibia 112 mm. The latter is 20% longer than the femur, which is an adaptation correlated with the ability to display great speed. Therefore they were good runners.

In various investigations its anatomical characteristics were determined. Some of these were autapomorphy, that is, it is exclusive to a particular organism or group. Rauhut in his 2000 study noted that his scapula is thinner than that of Coelophysis bauri. Previously in 1998 Chatterjee noticed peculiarities synapomorphic.

These consist of an accessory maxillary fenestra, vomers fused and extended to the choanaa characteristic single square head and fused orbitosphenoids.

Habitat

This dinosaur lived in a relatively dry indoor environment, where it could ingest large quantities of insects, lizards and other small animals. Lived with others coelophysoid such as Halticosaurus, Dolichosuchus, Plateosaurus gracilis and Efraasia minor.

Behavior

Being a small carnivore that had to hunt other animals for food, it could behave aggressively to catch its prey. However, that wouldn’t help him much against larger animals, which he could only defend himself against if he ran at high speed.

Speed

There is no study that specifies the speed at which Procompsognathus could run. But the study of its characteristics was indicative that it was made to run and that in fact it was its only defense against a predator.

When did Procompsognathus become extinct?

The fossil remains place Procomsognathus between 222 and 219 million years ago. They were small and some doubt that it was a dinosaur. Furthermore, there was a very distant stage, so it is not yet possible to know what factors could have contributed to its extinction.