The Prehistoric Croc Thread- Anything crocodilian related

Researchers excavated the remains of four of these now-extinct sea monsters from the rocky slopes of the Austrian Alps. But even at 13 feet long (4 meters), these creatures — known as phytosaurs — weren't fully grown.
The phytosaurs were only about 8 years old when they died, and they were "still actively growing," according to a bone analysis

University of New South Wales palaeontologists who found the fragment of crocodile jaw state that this individual was at least eight metres long and there may have been others of its kind that were even larger, perhaps reaching the size of Sarcosuchus, a twelve metre long Crocodylian that lived during the Late Cretaceous geological period and preyed on dinosaurs.

The fossil was discovered by undergraduate Bok Khoo from the University of New South Wales on July 10th, it is part of the lower jaw (dentary). The fossil bearing strata consists of several layers which represent ancient river deposits. The dig site is close to the current course of the Liechardt River and the sediment is disturbed when the water levels rise and this helps to expose new fossil finds. The river may help reveal fossil material but being close to the river does have its drawbacks. The location is known for its Saltwater and Freshwater crocodiles as well as sharks and sting rays. The field team have to be wary of attacks from extant crocodiles as they search for the fossilised remains of extinct ones.

Gilbert Price, a palaeontologist with Queensland University has commented that the jaw bone represents a substantial individual, one crocodile that was very probably an apex predator in the region. The fossil has yet to be accurately dated, it belongs to either the Pleistocene or the earlier Pliocene Epoch. The Pliocene ended approximately 1.6 million years ago, the Pleistocene Epoch followed and lasted until approximately 10,000 years ago. The fossil is eroded, a result of the river action and the teeth have been lost but the tooth sockets which measure up to four centimetres in diameter indicate that this predator had very large, conical-shaped teeth.

Professor Mike Archer of the University of New South Wales described the fossil as “weird” and he could not rule out that this fossil find could represent a new species.

Preserved for approximately 120 million years in a calcareous concretion, it was discovered in Villa de Leyva by Carlos Gonzalez. It is a partial fossil, albeit very well preserved. The state of the armoured plates (known as “osteoderms”), dorsal ribs, dorsal centra and metapodial elements indicate rapid burial shortly after death. The species of this fossil is unknown as neither teeth nor cranial elements were found. Several ammonites found in association with this fossil indicate its age, and the surrounding sediment suggests that when this crocodylomorph met its end, the area may have been a “a salt tidal flat depositional environment.”

Studying the microscopic structure of the bone (“osteohistology”) provided fascinating insight into the life of this creature. The size of the bones discovered, as well as the density of blood vessels within those bones, indicates that this reptile was an enormous creature. But even the 9.6-meter estimate is conservative, because larger vertebrae for this specific animal may have existed, but they were not preserved in the concretion.

Further osteohistological research revealed lines within the osteoderms. Much like the rings of a tree, the rings in a proboscidean tusk or information contained with fossil teeth, paleontologists can read these lines to infer whether this reptile experienced times of famine and hardship, as well as how seasons may have affected its level of activity or overall health.

Unfused neurocentral sutures suggested the fossil was an adult, but not one that was fully mature at the time of its death.

Theropod dinosaurs were relatively scarce in the Late Cretaceous ecosystems of southeast Brazil. Instead, hypercarnivorous crocodyliforms known as baurusuchids were abundant and probably occupied the ecological role of apex predators

Millions of years ago, several genera and species of crocodiles lived in Europe, and occassionally coexisted with each other. Among these, however, it was considered unlikely that the genus Crocodylus, of African origin, had ever lived in the Mediterranean.

The remains found in the Italian regions of Gargano, Tuscany and Scontrone during the last decades however confirm that they did. Now, a study published by the Journal of Paleontology supports this with more fossils of three-meter long crocodiles found at the Valencian fossil site Venta del Moro, dug up by researchers of the University of Valencia between 1995 and 2006- and which they assigned at one point to the species Crocodylus chechhiai.

Our comparisons show this material does not belong to the genera Duplocynodon- an alligatoroid genus similar to today's caiman- or Tomistoma- the false gharials-, the only other crocodilians known for the late Miocene of Europe.

However, due to the fragmentary nature of the remains, the analysis of the skull bones, isolated teeth and osteoderms (bone plates) suggests they could belong to the species C. checchiai, as originally assigned, but its taxonomy is still unclear. In any case the morphology fits genus Crocodylus.

The remains would be the first Crocodylus from the Iberian penninsula and support the expansion of this genus from Africa to Europe during the late Miocene. The discovery of two individuals rather than one indicates there was a population at the site (as opposed to a vagrant that ended up away from home).

In their "conquest", these reptiles expanded particularly around the Mediterranean, as the remains have been found in Spain and Italy. All locations where crocodilians have been found were back then near the northern coastline of the Mediterranean, thus making it easy to access by crocodiles traveling by sea.

They are likely to have inhabited the coasts of Murcia and Andalusia, and perhaps even Catalunya and the Balearic islands.

But how did crocodiles arrive from the African coasts? The researchers suggest they swam from one continent to the next before Africa and Europe were connected. This idea would be supported by modern crocodile behavior, as they are good swimmers that can reach up to 32 km/h.

An example is today's saltwater crocodile (Crocodylus porosus), which goes far into the open sea reaching islands and even continents, as has happened between Oceania and the south east of Asia. One needs only see how easily they have traveled to even the Solomon islands of the French Polynesia.

But there are more clues that support the hypothesis. The anatomical similarities suggest Crocodylus checchiai, of Lybia and Kenya, is the ancestor of American crocodiles. This suggests crocodiles even crossed the Atlantic during the Miocene, explaining the presence of the genus in the New World.

As such, in the case of the Venta del Moro specimens, swimming between Africa and Europe would not have taken them a particularly great effort.