Compsognathus ‭(‬Pretty jaw‭)

Short Info

Compsognathus ‭(‬Pretty jaw‭)

Phonetic : Komp-sog-nath-us.

Named By : Johann Andreas Wagner‭ ‬-‭ ‬1861

Diet : Carnivore

Size : Estimated 125-650cm long

Type of Dinosaur : Small Theropod

Type Species : C.‭ ‬longipes‭ (‬type‭)

Found in : Germany,‭ ‬France,‭ ‬Possibly Portugal

When it Lived : Late Jurassic, 145-140 million years ago

Compsognathus (/kamp’sagn@th@sCompsognathus (/kamp’sagn@th@s Greek kompsos/kompsos “elegant”, “refined” or “dainty”, and gnathos/gnathos; “jaw”) is an genus that is small, carnivorous, bipedal dinosaurs. The species comprising Compsognathus longipes can reach the size of an average turkey. They lived around 150 million years back in the Tithonian age in that late Jurassic period in the present-day Europe. Paleontologists have discovered two well-preserved fossils. One was found located in Germany during the early 1850s, and the other one in France over one century later. In the present, C. longipes is the only species recognized however the more extensive specimen found by researchers in France from the late 1970s believed to be an entirely different species, and was called C. corallestris.

CompyZach Tirrell from Plymouth, USA, CC BY-SA 2.0, via Wikimedia Commons

Some presentations still refer to Compsognathus being “chicken-sized” dinosaurs because of the size of the German specimen that is now considered to be an adult. Compsognathus longipes is among the rare dinosaurs that can be identified with certainty. The remains of tiny agile lizards have been preserved within the stomachs of the two specimens. Teeth found in Portugal could be fossil remains from the Genus.

Although it was not considered a dinosaur when it was first discovering, Compsognathus is the first theropod dinosaur discovered from a fairly full fossilized skeleton. Up until the 1990s, it was the least-known non-avialan dinosaur. prior centuries mistakenly labeling Compsognathus as the closest relative of Archaeopteryx.

Compsognathus longipes cast 3User:MatthiasKabel, CC BY-SA 3.0, via Wikimedia Commons

Compsognathus is identified through two skeletons that are almost complete. This German piece (specimen BSP AS I 563) BSP AS I 563) originates from limestone deposits within Bavaria which was part of the personal collection belonging to the doctor as well as fossil collector, Joseph Oberndorfer. Oberndorfer donated his specimen to the Paleontologist Johann A. Wagner, who wrote a short discussion in 1859, during which he proposed the name Compsognathus longipes. Wagner didn’t recognize Compsognathus to be a dino however, he did describe him as one of “most curious forms among the lizards”. Wagner published a more thorough account in 1861. In 1866, the collection of Oberndorfer comprising his Compsognathus sample, was purchased by the paleontological state collection of Munich.

The date of discovery as well as the precise location of the German specimen aren’t known probably because Oberndorfer didn’t disclose specifics of the discovery to deter others from taking advantage of the location. The weathering of the slab where the fossil was preserved suggests that it came from a heap of rock waste left after quarrying. The fossil could be from Jachenhausen or from the Riedenburg-Kehlheim region. Each of the possible sites is part of the lagoonal deposits from the Painten Formation and are dated to the latter portion of the later Kimmeridgian or earlier parts of the Tithonian. In the Jurassic region, it formed part of the Solnhofen archipelago. The limestone in the region is known as Solnhofen limestone, Solnhofen limestone, was quarryed for a long time and produced fossils that were well preserved such as Archaeopteryx that had feather prints, and the pterosaurs, which had imprints from their wings membranes.

In two articles published from 1868 and 1870 Thomas Huxley, a major advocate of Darwin’s theory of evolutionary change was able to compare Compsognathus with Archaeopteryx that was thought to be to be the first bird known. Based on earlier theories by Karl Gegenbaur and Edward Drinker Cope, Huxley found that Archaeopteryx was very identical to Compsognathus and described the former as being a “bird-like reptile”. Huxley concluded that birds must be a descendent of dinosaurs, a conclusion that confirmed Compsognathus as being among the most well recognized dinosaurs. The fossil has been studied by numerous notable paleontologists, including Othniel Charles Marsh who travelled to Munich on the 18th of August 1881. It was the German Paleontologist J.G. Baur who was an assistant to Marsh who was the Marsh’s assistant, took his right leg from the slab in order to provide research and illustration; the removed portion was lost after. Even though Baur published a comprehensive analysis of his ankle back in 1882 that is currently the only accessible source of information about the skeleton’s lateral limbs The reconstruction he made was later discovered to be uncongruous with impressions made on the slab. John Ostrom thoroughly described the German specimen, as well as the recently discovered French sample in the year 1978. which made Compsognathus one the most famous tiny theropods of the time.

The more substantial French sample (MNHN CNJ 79) was found in 1971, in Portlandian limestone lithographic of Canjuers close to Nice. It dates back to the lower Tithonian as shown by the ammonite-based index fossils. In Solnhofen states, Canjures is famously known for the limestone plate that were mined and sold under the brand name “dalles de Provence”. The specimen was initially part of the private fossil collection owned by Louis Ghirardi, the owner of the Canjures quarries. The collection, which included that Compsognathus fossil, donated by the National Museum of Natural History in Paris in 1983. Alain Bidar and Gerard Thomel in a short 1972 article, described the discovery under a distinct species called Compsognathus corallestris. A more thorough description was released within the year. According to the authors, the new species was different in comparison to the German species due to its larger size as well as its modified flipper-like hands. Ostrom, Jean-Guy Michard and others have since classified the new species as an additional example from Compsognathus Longipes. The year 1984 was when George Callison and Helen Quimby identified the smaller German specimen as an adult of the same species.

The collector Heinrich Fischer had originally labeled the foot, which was comprised of three metatarsals, as well as an phalanx, which was found in the Solnhofen region, as belonging to Compsognathus longipes. The identification was not accepted by Wilhelm Dames, when he described the specimen first time, in the year 1884. Friedrich von Huene, in 1925 and 1932, observed that the foot most likely belonged to Compsognathus as such but was another genus closely related to it. 336 Ostrom in his monograph of 1978, challenged the validity the fossil Compsognathus again. Jens Zinke was credited in 1998 with assigning forty-nine tooth fragments of the Guimarota coal mine in Portugal to the Genus. Zinke discovered that the teeth were not the same as the teeth of Compsognathus longipes. They have serrations along the front edges and therefore classified these teeth Compsognathus sp. (of an unknown species).

For a long time, Compsognathus was known as the smallest non-avian dinosaur known but some dinosaurs found later, like Mahakala and Microraptor were much smaller. This German specimen was calculated to be between 70 and 70 centimeters (28-30 inches) and 89cm (35 inches) in length, according to different writers, and the bigger French sample was measured to be 1.25 m (4 1 inch)) and 1.4 meters (4 7 inches) to be the length. The hip’s height was estimated to be 21 centimeters (8.3 inches) on the German specimen, and at 29 centimeters (11 inch)) in that of the French specimen. This German specimen was found to weigh 0.32 kg (0.71 lbs) in addition to 0.58 kg (1.3 lbs) as well as the French specimen weighed 2.5 kg (5.5 lbs) in weight and 3.5 kg (7.7 lbs). Comparatively to other compsognathids the bigger French specimen is comparable in size to the larger Sinosauropteryx specimens, however less in comparison to Huaxiagnathus as well as Mirischia.

Compsognathus were tiny bipedal mammals with long hind legs as well as longer tails. They employed to balance when they moved. Forelimbs were less limb-length than hindlimbs. The hand had two huge clawed fingers and an additional, smaller digit, which could be non-functional. The delicate skulls of the ancients were thin and long. They also had snouts that were tapered. The skull contained five pairs of Fenestrae (skull openings) which was the largest that was used specifically for the orbit (eye socket) and the eyes being bigger relative to that of other parts of the skull. Lower jaws were thin and did not have a mandibular fenestra or a hole on the lower jawbone’s side typically seen in archosaurs.

The teeth were narrow and pointed, making them suitable to eat tiny vertebrates and maybe other animals of a smaller size like insects. The German specimen contained 3 teeth per premaxilla (front bone of the lower jaw) with 15 or 16 maxilla teeth, as well as 18 lower jaw teeth. The French specimen was more tooth-filled with four teeth in each premaxilla, and 17 or 18 on the maxilla as well as at least 21 dental teeth. Compsognathids were distinct among theropods with tooth crowns that turned forward at about two-thirds of their height. In addition, their mid-portions were straight Also, the crowns were enlarged in their bases. In Compsognathus the front teeth of the lower and upper jaws were unreserrated, while the teeth further back had serrations that were fine on the rear of their edges. The German specimen the crowns were about two times wider than they were at the front of the jaws, however they were lower farther back. The final tooth nearly as high as wide. In addition, the German specimen also has the diastema (tooth gap) in the middle of the first three teeth on the upper premaxilla. Because a tooth gap wasn’t present within the French specimen, Peyer suggested that additional teeth could be found in the region of on the German specimen.

Hands with digits of the number 3 on Compsognathus is a subject of discussion. In the early years of its history, Compsognathus was typically depicted with three digits, which is the norm for theropods. However the type specimen retained phalanges from the initial two digits, which led to the idea that Compsognathus had only two digits that were functional, and the third metacarpal was extremely thin and narrow. The study on the French specimen revealed that the last digit had at most one or two tiny phalanges. But, there is no evidence for an unnatural 3rd digit phalanx and, therefore, the digit could have been reduced , and therefore non-functional.

Source: Wikipedia