An elongated tail ending in a rhombus-shaped tip and pointed forward-facing teeth are some of the peculiar characteristics of the Ranforrincos, a type of pterosaur found near the city of Calama that inhabited the megacontinent Gondwana about 160 million years ago. years. Jhonatan Alarcón, a researcher at the Paleontological Network of the University of Chile, led the research that demonstrates the global distribution of these winged reptiles, a work that was published by the journal Acta Palaeontologica Polonica.
In 2009, a hammer blow to a block of rock with a spherical shape by the director of the Museum of Natural and Cultural History of the Atacama Desert, Osvaldo Rojas, gave light, after 160 million years, some very fossil remains. well preserved of an unknown species. The finding was made during an expedition to the town of Cerritos Bayos, located 30 kilometers southwest of Calama , in the Atacama Desert, where other extraordinary paleontological finds have been made, mainly of the marine fauna that inhabited the place at the end of the Jurassic period, when South America was part of the Gondwana megacontinent.
However, later analysis allowed to determine that the discovered specimen was not this time a prehistoric marine animal, but an extraordinary flying reptile from the Jurassic period, more precisely a pterosaur from the Ramphorhynchinae subfamily. Jhonatan Alarcón, from the Paleontological Network of the University of Chile, led the study of these remains corresponding to “a left humerus, a possible dorsal vertebra and two fragments of a phalanx of the wing, all preserved in three dimensions and probably belonging to a single individual “, work developed together with the researchers of the Paleontological Network of the University of Chile Rodrigo Otero , Sergio Soto-Acuña and Alexander Vargas, and researchers Jennyfer Rojas and Osvaldo Rojas , from the Museum of Natural and Cultural History of the Atacama Desert
According to the paleontologist, the preserved pieces of this specimen – published in the journal Acta Palaeontologica Polonica – are enough to determine that it is a large-scale pterosaur for that time, probably very similar to the members of a group known essentially in the Northern Hemisphere called Rhamphorhynchinae, of which genera such as Rhamphorhynchus from Europe or Nesodactylus from Cuba are part. ” These pterosaurs had wing spans, tip to tip, of up to 1.80 or 2 meters. Our specimen is quite large, comparable to Rhamphorhynchus, which is the largest member of this family, or perhaps the largest .”
These enigmatic winged dragons, explains Jhonatan Alarcón, were characterized by “having a very long tail and a peculiar rhombus-shaped ending. They also had low heads, long snouts, and pointed forward teeth . Based on the size, especially the humerus, which looks very developed, and also based on comparisons with other specimens, we can say that it corresponds to an adult or a state very close to the adult stage. “He also adds that they have been able to “rescue other bones in the area of the discovery, materials that still have to be studied to determine whether or not this specimen corresponds to a new species, which is the most probable.”
A valuable piece of the Jurassic
This is the first specimen of the Rhamphorhynchinae subfamily discovered in the Southern Hemisphere , particularly in territories of the former Gondwana megacontinent. “What is there even before this discovery are teeth found in Morocco, still assigned with doubts. Ours is the first 100 percent confirmed and they are also the first skeletal remains of this group. All the discoveries of the subfamily Rhamphorhynchinae come essentially from the northern hemisphere, mainly from Europe. With this, we demonstrated that the distribution of the animals in this group was broader than what was known up to now ”, he comments.
At the local level, on the other hand, it is the first Jurassic pterosaur found so far in Chile and, therefore, the oldest representative of these winged lizards in the country . “Jurassic pterosaurs have already been found in South America, but this is the first one discovered in Chile. In addition, it is preserved in a three-dimensional way, which is rare, since pterosaurs in general are preserved with crushed bones, given that they had very delicate and pneumatic bones, adapted for air movement ”. Alarcón also suggests that this is the first pterosaur identified to have inhabited Gondwana during the Oxfordian, a specific geological age of the late Jurassic that extends from 161.2 to 155.7 million years ago.
Cerritos Bayos is the specific place of this and other important paleontological finds that show how different the environment of the Atacama Desert was during the late Jurassic. This area contains a great diversity of marine deposits from this period, made up of sandstones deposited in marine waters with coastal influence, in which abundant remains of ammonites (mollusks with shell relatives of the octopus and squid) and fish have also been found, which they probably were part of the pterosaur diet .
This is how last year the same team from the Paleontological Network of the U. de Chile announced the discovery of plesiosaurs of the genera Muraenosaurus and Vinialesaurus, and also the first remains of pliosaurs (relatives of plesiosaurs, but with large skulls and short neck). The researchers also detail that in the place there is also a multiplicity of marine crocodiles, ichthyosaurs and giant fish, among other animals that are under investigation and that they hope to make known soon.
The identification of this pterosaur, the first animal found in this coastal ecosystem that was not strictly aquatic, also adds background on the strong link between the fauna of Gondwana – made up of territories such as South America, Antarctica, Africa, Madagascar, India and Australia – and Laurasia – made up mainly of North America, Asia and Europe. “ This finding adds evidence to the connection that occurred between the Northern and Southern hemispheres , particularly through a Caribbean passage that existed in the Jurassic, as has already been supported by marine reptiles such as the Muraenosaurus genus, found in the United Kingdom, France. and Argentina, and Vinialesaurus, found in marine deposits in Cuba ”.
Regarding the presence of the Rhamphorhynchinae subfamily in Gondwana, Alarcón states that the flying capacity of this animal certainly facilitated its mobility. “There are pterosaurs of this group also in Cuba, which apparently were coastal animals, so most likely they have migrated between the north and south or maybe they came once and stayed, we don’t know, but most likely is that these pterosaurs moved near the coast, since their diet consisted mainly of marine animals.