What adaptations did the Odontochelys semitestacea have?

Was Odontochelys an aquatic animal?

It is likely that Odontochelys was aquatic, as the fossil specimens were found in marine deposits rife with conodonts and ammonites. It is theorized that the primitive turtle frequented shallow marine waters close to shore.

What are the differences between Odontochelys fossils and modern turtles?

In contrast, Odontochelys fossils were found to have had teeth embedded in their upper and lower jaws. One of the most striking features of turtles, both modern and prehistoric alike, are their dorsal shells, forming an armored carapace over the body of the animal. Odontochelys only possessed the bottom portion of a turtle’s armor, the plastron.

What does Odontochelys semitestacea mean?

The species’ name, Odontochelys semitestacea literally means “toothed turtle with a half-shell” – an apt descriptor of its most striking physical characteristics. ^ a b c d e Li, Chun; Xiao-Chun Wu, Olivier Rieppel, Li-Ting Wang & Li-Jun Zhao (2008-11-27).

When was the first Odontochelyidae species discovered?

It is the only known species in the genus Odontochelys and the family Odontochelyidae. The species was first described from three 220 million year-old specimens excavated in Triassic deposits originating from Guizhou, China. As a primitive turtle, Odontochelys grossly differed from modern turtles in several ways.

What are the characteristics of an Odontochelys turtle?

One of the most striking features of turtles, both modern and prehistoric alike, are their dorsal shells, forming an armored carapace over the body of the animal. Odontochelys only possessed the bottom portion of a turtle’s armor, the plastron. It did not yet have a solid carapace as most other turtles do.

Was the Odontochelys a terrestrial or aquatic reptile?

Even though the Odontochelys specimens were found in marine deposits, there is uncertainty over whether it was a primarily aquatic reptile, in transition from aquatic to terrestrial habitats, or fully terrestrial. Li et al.

Why does the Odontochelys have a shell?

Although Odontochelys has only a partial shell protecting its back, it does have a fully formed plastron – complete protection of its underside – just as turtles do today. This strongly suggests Odontochelys was a water dweller whose swimming exposed its underside to predators, Rieppel said.

Is Odontochelys the oldest species of pterosaurs?

Before Pappochelys was discovered and Eunotosaurus was redescribed, Odontochelys was considered the oldest undisputed member of Pantestudines (i.e. a stem -turtle). It is the only known species in the genus Odontochelys and the family Odontochelyidae .

What is the difference between Proganochelys and Odontochelys?

In contrast to Odontochelys, the shell of Proganochelys possessed most of the features of modern turtles, and it completely encased the shoulder and pelvic girdles. Although Odontochelys, Proganochelys, and Eunotosaurus offer insight into early anatomy, the origin of turtles remains a strongly debated issue.

Is Odontochelys the most primitive fossil ever found?

Taken together, these anatomical differences have been interpreted by the discoverers to mean that Odontochelys has some of the most primitive features ever seen in a turtle and is somewhat of a transitional fossil. It is likely that Odontochelys was aquatic, as the fossil specimens were found in marine deposits rife with conodonts and ammonites.

What is the difference between modern and prehistoric turtles?

Modern turtles have a horny beak without teeth in their mouth. In contrast, Odontochelys fossils were found to have had teeth embedded in their upper and lower jaws. One of the most striking features of turtles, both modern and prehistoric alike, are their dorsal shells, forming an armored carapace over the body of the animal.

When did dinosaurs first appear?

They first appeared during the Triassic period, between 243 and 233.23 million years ago, although the exact origin and timing of the evolution of dinosaurs is the subject of active research.

What is the most adapted reptile to its environment?

Besides the sea turtles, the sea snakes are the reptiles that are best adapted to marine environments. The most typical feature of a sea snake is the vertically flattened paddle-like tail, which is not found in any other terrestrial or aquatic snakes (Figure 5).

How many reptile species have re-entered the ocean?

Of the more than 12,000 species and subspecies of extant reptiles, about 100 have re-entered the ocean.

What makes the Odontochelys different from other turtles?

Aside from the presence of teeth and the absence of a solid carapace, a few other skeletal traits distinguish Odontochelys as basal compared to other turtles, extant and otherwise. The point of articulation between the dorsal ribs and the vertebrae is decidedly different in Odontochelys than in later turtles.

Is Proganochelys a turtle or a fish?

Proganochelys fits well into the order as a turtle, as the shell of Proganochelys is in agreement with the evolution of other stem-turtles. The dermal roofing elements of Proganochelys include a large nasal, a fully roofed skull, a flat squamosal, and an absent pineal foramen.

Does Proganochelys have a fully formed shell?

Because Proganochelys has a fully-formed shell, it provides little information about how shells were formed. Odontochelys is older than Proganochelys and is helpful because it has only a partial shell, Rieppel said.

Were prehistoric turtles and tortoises really locked into their body plans?

By the early Jurassic period, about 200 million years ago, prehistoric turtles and tortoises were pretty much locked into their modern body plans, though there was still room for innovation.

Are turtles an ancestral reptiles?

Ancestral turtles and tortoises branched off from the mainstream of reptile evolution hundreds of millions of years ago, and have persisted pretty much unchanged down to the present day.

What kind of turtles lived in the Cretaceous period?

The most notable turtles of the Cretaceous period were a pair of marine giants, Archelon and Protostega, both measuring about 10 feet long from head to tail and weighing about two tons. As you might expect, these giant turtles were equipped with broad, powerful front flippers,…

Which group of reptiles eventually produced the dinosaurs?

It was the diapsid group of the reptiles that eventually produced the dinosaurs. The jaw muscles in these reptiles were attached to the two openings on each side of the skull, giving their jaws better leverage and strength. Sometime in the Permian period, the diapsid line branched into two groups: lepidosaurs and archosaurs.