Oldest oceanic reptile ecosystem from the Age of Dinosaurs discovered on Arctic island

More than 30,000 tooth, bones and different fossils from a 249 million-year-old group of extinct marine reptiles, amphibians, bony fish and sharks have been found on the distant Arctic island of Spitsbergen. These document the earliest radiation of land-living animals into oceanic ecosystems following cataclysmic extinction and excessive world warming on the daybreak of the Age of Dinosaurs.

The fossils have been present in 2015, however took practically a decade of painstaking work to excavate, put together, type, establish, and analyze. The long-awaited analysis findings have now been printed by a crew of Scandinavian paleontologists from the Natural History Museum on the University of Oslo, and the Swedish Museum of Natural History in Stockholm.

The paper is published within the journal Science.

Spitsbergen within the Svalbard archipelago is world well-known for producing marine fossils from the start of the Age of Dinosaurs. These are preserved in rock layers that have been as soon as mud on the backside of a sea stretching from mid-to-high paleolatitudes and bordering the immense Panthalassa super-ocean. Most spectacular are the stays of weird marine reptiles and amphibians that symbolize the earliest adaptive specialization of land-living animals for all times in offshore habitats.

The aftermath of Earth’s best extinction

Textbooks recommend that this landmark evolutionary occasion came about after probably the most catastrophic mass extinction in Earth historical past, some 252 million years in the past. Termed the end-Permian mass extinction, this “great dying” worn out over 90% of all marine species, and was pushed by hyper-greenhouse situations, oceanic deoxygenation, and acidification linked to huge volcanic eruptions initiating the breakup of the traditional Pangaean supercontinent.

Timing the restoration of marine ecosystems after the end-Permian mass extinction is among the most debated subjects in paleontology as we speak. The long-standing speculation is that this course of was gradual, spanning some eight million years, and concerned a stepwise evolutionary development of amphibians and reptiles successively invading open marine environments. However, the invention of the brand new and exceptionally wealthy fossil deposit on Spitsbergen has now upended this conventional view.

The Spitsbergen fossil deposit is so dense that it really varieties a conspicuous bonebed weathering out alongside the mountainside. This accrued over a really quick geological timeframe, and due to this fact gives unprecedented insights into the construction of marine communities from just a few million years after the end-Permian mass extinction. Stratigraphic relationship has pinpointed the age of the Spitsbergen fossil bonebed to round 249 million years in the past.

Revealing a fast restoration and wealthy range

Careful assortment of the stays from 1 m² grids masking 36 m² has additionally ensured that over 800 kg of fossils, together with every part from tiny fish scales and shark tooth to massive marine reptile bones and even coprolites (fossilized feces) have been recovered.

The Spitsbergen fossil bonebed reveals that marine ecosystems bounced again extraordinarily quickly, and had established complicated meals chains with quite a few predatory marine reptiles and amphibians by as little as three million years after the end-Permian mass extinction. Most stunning is the sheer range of totally aquatic reptiles, which included archosauromorphs (distant kinfolk of contemporary crocodiles) and an array of ichthyosaurs (“fish-lizards”) ranging in dimension from small squid-hunters lower than one meter lengthy to gigantic apex-predators exceeding 5 meters in size.

A pc-based world comparative evaluation of the assorted animal teams additional highlights the Spitsbergen fossil bonebed as one of the species-rich marine vertebrate (backboned animal) assemblages ever found from the daybreak of the Age of Dinosaurs. It additionally means that the origins of sea-going reptiles and amphibians are a lot older than beforehand suspected, and certain even preceded the end-Permian mass extinction.

This ecosystem reset would have opened new feeding niches, and in the end, laid the foundations for contemporary marine communities as we all know them as we speak.