In a new study published in the June 2021 issue of Earth Science Reviews, an explanation of the mystery of ancient fossils discovered in the Antilles Islands in Central America, which contained fossils of ancient wild animals that had originated in South America.

The study attributed the reason to areas of land that were land transport bridges between the two Americas, but they sank long ago in the depths of the ocean as a result of several factors, the most important of which may be the movement of tectonic plates and the melting of glaciers over the ages.

There were stretches of land that served as land transport bridges between the Americas, but they sank long ago in the depths of the ocean (Shutterstock)

simulating the movement of tectonic plates

According to the Science Alert report, researchers from French, British and Romanian universities collaborated to develop a model to simulate nearly 40 million years of plate tectonic movement at the underwater boundary of the Lesser Antilles, the Greater Antilles and the Aves Ridge.

The researchers took into account the role of sea level rise and fall over 1.5 million years, because of its significant impact on the emergence and disappearance of these huge islands "archipelagoes".

The seismic data that was monitored in the area over the past 40 million years was also studied, in addition to an assessment of the current geography of the islands.

Thus, with the help of a computer model, researchers were able to understand the mechanism of formation and disintegration of land masses again, over millions of years until the late Eocene, a geological epoch that lasted from 56 million years to 34 million years.

The beginning of the Eocene era was marked by the emergence of modern mammals and ended with a massive mass extinction believed to have resulted from the collision of a giant meteorite with the Earth in the region of Siberia at the time.

Simulated approximately 40 million years of plate tectonic movement at the tangency of the Lesser and Greater Antilles and the Mount Avis Ridge (Earth Science Reviews)

Future studies targeting the Caribbean

The Antilles are the archipelago located between the Caribbean Sea, the Atlantic Ocean, and the Gulf of Mexico.

It is divided into two main groups, the Greater Antilles, which lies to the north and includes Cuba, Jamaica, Hispaniola and Puerto Rico, and the Lesser Antilles, which includes the Leeward Islands, Windward Islands, and the offshore islands of Venezuela.

Researchers believe that these huge archipelagos and islands were very common in the past, as they appear and persist over several millions of years and then disappear later for millions more.

Here we can note that Russia and Canada were connected in the past, as well as the United Kingdom was connected with the rest of Europe.

Given the paucity of studies on the Antilles region, this study is the first of its kind to provide a simulation model that deals with so much detail and factors that can affect the entire region.

Using this improved model, the researchers hope to expand their study further south to cover the entire Caribbean plate.

The role of the Lesser Antilles in the distribution of wild animals over the past 40 million years needs to be re-evaluated (Wikipedia)

With these results, researchers continue to search for a more complete fossil record for the Lesser Antilles, as well as the need to better visualize the geography of the ancient region between Guadeloupe and Venezuela, in order to more accurately identify previously existing land travel routes.

The researchers concluded that "the role of the Lesser Antilles in the distribution of terrestrial animals over the past 40 million years must be re-evaluated."