Ancient Marine Reptile May Have Hunted Bioluminescent Fish At Night

When Tyrannosaurus rex prowled the land, the oceans of the Late Cretaceous werent particularly safe either. Cruising the waters at the time were large predatory reptiles known as mosasaurs, elongated and streamlined for hunting down their prey in the warm shallow seas. Some of these were true beasts reaching up to 18 meters (59feet) in length, but others were a little more modest. Researchers have revealed the first mosasaur of its kind to be discovered in Japan, and discovered that it probably hunted at night using binocular vision.

The marine reptile in question is a species called Phosphorosaurus ponpetelegans, and came in at a relatively tiny for mosasaur at least 3 meters(10 feet) long. The remarkably well preserved skull is the only example known from Japan, and helps palaeontologists fill a geographic gap of the species from between the Middle East and the eastern Pacific. It also allows the researchers to determine that the animal quite possibly fed on bioluminescent fish and squid during the night, whilst their larger cousins dominated the sea during the daytime.

The forward-facing eyes on Phosphorosaurus provide depth perception to vision, and it’s common in birds of prey and other predatory mammals that dwell among us today, explains Takuya Konishi in a statement. Konishi is acoauthor of the study, which is published in the Journal of Systematic Palaeontology. But we knew already that most mosasaurs were pursuit predators based on what we know they preyed upon swimming animals. Paradoxically, these small mosasaurs like Phosphorosaurus were not as adept swimmers as their larger contemporaries because their flippers and tailfins weren’t as well developed.

But when compared to their larger relatives, the vision of Phosphorosaurus is markedly different. On the bigger specimens, their eyes are located on either side of their head not unlikea horse or deer today which is thought to have helped streamline the reptile and allow it to swim faster to catch the turtles, sharksand other mosasaurs they fed on.

With the smaller species, however, the eyes are forward facing, which in nocturnal animals doubles the number of photoreceptors used to detect light. Because fossils of lantern fish and squid-like animals have been found in the same rock formations in Japan as Phosphorosaurus, the researchers suggest that the reptilemight have been hunting at night. They even go on to postulate that perhaps this might have been a larger trend for other species of mosasaurs, with the larger animals hunting and chasing down prey during the day, whilethe smaller, more vulnerable ones only came out at night.

The excavation of the skull that enabled this discovery took a painstaking two years. It involveddipping the rock in which it was encased in acid overnight, and then washing it off every morning, gradually freeing the bones. These werethen pieced togetherto re-create the original skull. The researchersnow intend to look into how the species fits into the evolutionary tree of mosasaurs.

Source: http://www.iflscience.com

Ancient Marine Reptile May Have Hunted Bioluminescent Fish At Night

When Tyrannosaurus rex prowled the land, the oceans of the Late Cretaceous werent particularly safe either. Cruising the waters at the time were large predatory reptiles known as mosasaurs, elongated and streamlined for hunting down their prey in the warm shallow seas. Some of these were true beasts reaching up to 18 meters (59feet) in length, but others were a little more modest. Researchers have revealed the first mosasaur of its kind to be discovered in Japan, and discovered that it probably hunted at night using binocular vision.

The marine reptile in question is a species called Phosphorosaurus ponpetelegans, and came in at a relatively tiny for mosasaur at least 3 meters(10 feet) long. The remarkably well preserved skull is the only example known from Japan, and helps palaeontologists fill a geographic gap of the species from between the Middle East and the eastern Pacific. It also allows the researchers to determine that the animal quite possibly fed on bioluminescent fish and squid during the night, whilst their larger cousins dominated the sea during the daytime.

The forward-facing eyes on Phosphorosaurus provide depth perception to vision, and it’s common in birds of prey and other predatory mammals that dwell among us today, explains Takuya Konishi in a statement. Konishi is acoauthor of the study, which is published in the Journal of Systematic Palaeontology. But we knew already that most mosasaurs were pursuit predators based on what we know they preyed upon swimming animals. Paradoxically, these small mosasaurs like Phosphorosaurus were not as adept swimmers as their larger contemporaries because their flippers and tailfins weren’t as well developed.

But when compared to their larger relatives, the vision of Phosphorosaurus is markedly different. On the bigger specimens, their eyes are located on either side of their head not unlikea horse or deer today which is thought to have helped streamline the reptile and allow it to swim faster to catch the turtles, sharksand other mosasaurs they fed on.

With the smaller species, however, the eyes are forward facing, which in nocturnal animals doubles the number of photoreceptors used to detect light. Because fossils of lantern fish and squid-like animals have been found in the same rock formations in Japan as Phosphorosaurus, the researchers suggest that the reptilemight have been hunting at night. They even go on to postulate that perhaps this might have been a larger trend for other species of mosasaurs, with the larger animals hunting and chasing down prey during the day, whilethe smaller, more vulnerable ones only came out at night.

The excavation of the skull that enabled this discovery took a painstaking two years. It involveddipping the rock in which it was encased in acid overnight, and then washing it off every morning, gradually freeing the bones. These werethen pieced togetherto re-create the original skull. The researchersnow intend to look into how the species fits into the evolutionary tree of mosasaurs.

Source: http://www.iflscience.com

Ancient Marine Reptile May Have Hunted Bioluminescent Fish At Night

When Tyrannosaurus rex prowled the land, the oceans of the Late Cretaceous werent particularly safe either. Cruising the waters at the time were large predatory reptiles known as mosasaurs, elongated and streamlined for hunting down their prey in the warm shallow seas. Some of these were true beasts reaching up to 18 meters (59feet) in length, but others were a little more modest. Researchers have revealed the first mosasaur of its kind to be discovered in Japan, and discovered that it probably hunted at night using binocular vision.

The marine reptile in question is a species called Phosphorosaurus ponpetelegans, and came in at a relatively tiny for mosasaur at least 3 meters(10 feet) long. The remarkably well preserved skull is the only example known from Japan, and helps palaeontologists fill a geographic gap of the species from between the Middle East and the eastern Pacific. It also allows the researchers to determine that the animal quite possibly fed on bioluminescent fish and squid during the night, whilst their larger cousins dominated the sea during the daytime.

The forward-facing eyes on Phosphorosaurus provide depth perception to vision, and it’s common in birds of prey and other predatory mammals that dwell among us today, explains Takuya Konishi in a statement. Konishi is acoauthor of the study, which is published in the Journal of Systematic Palaeontology. But we knew already that most mosasaurs were pursuit predators based on what we know they preyed upon swimming animals. Paradoxically, these small mosasaurs like Phosphorosaurus were not as adept swimmers as their larger contemporaries because their flippers and tailfins weren’t as well developed.

But when compared to their larger relatives, the vision of Phosphorosaurus is markedly different. On the bigger specimens, their eyes are located on either side of their head not unlikea horse or deer today which is thought to have helped streamline the reptile and allow it to swim faster to catch the turtles, sharksand other mosasaurs they fed on.

With the smaller species, however, the eyes are forward facing, which in nocturnal animals doubles the number of photoreceptors used to detect light. Because fossils of lantern fish and squid-like animals have been found in the same rock formations in Japan as Phosphorosaurus, the researchers suggest that the reptilemight have been hunting at night. They even go on to postulate that perhaps this might have been a larger trend for other species of mosasaurs, with the larger animals hunting and chasing down prey during the day, whilethe smaller, more vulnerable ones only came out at night.

The excavation of the skull that enabled this discovery took a painstaking two years. It involveddipping the rock in which it was encased in acid overnight, and then washing it off every morning, gradually freeing the bones. These werethen pieced togetherto re-create the original skull. The researchersnow intend to look into how the species fits into the evolutionary tree of mosasaurs.

Source: http://www.iflscience.com

Extinction Of Croc Ancestors Helped Out Cretaceous Turtles

A major drop in sea levels drove many crocodile ancestors to extinction around 145 million years ago at the boundary between the Jurassic and Cretaceous periods, according to new findings published in Proceedings of the Royal Society B. And this massive decline was a boon for early marine turtles.

Crocodyliforms used to be hugely diverse, and they have a much richer evolutionary history than youd expected judging from their living descendants, which include todays alligators and crocodiles. Some swam in the ocean and grew up to 12 meterslong (39 feet long), while others were much smaller and lived on land. Based on fossils, researchers have known about the extinction event at the Jurassic/Cretaceous (J/K) boundary for decades, but the effects of crocodyliform declines remained largely unstudied.

So, a trio of researchers led by Jonathan Tennant of Imperial College London turned to a digital archive called the Paleobiology Database to look for changes in longer-term trends in crocodyliform fossil records spanning 201 million to 66 million years ago.

They found a huge biodiversity crash across the J/K boundary: More than 75 percent of genera living on land and at sea were lost. While non-marine biodiversity partially recovered, marine biodiversity remained low throughout the Early Cretaceous. The remaining crocodyliformspecies diversified into new groups such as the now-extinct notosuchians, which were about 1.5 meterslong (5 feet long). The eusuchians came to prominence after the extinction event, and they led up to today’s crocodiles.

This massive decline was mostly caused by a drop in sea levels, which closed off shallow marine environments like the lagoons and coastal swamps where many crocodyliforms lived and hunted. Additionally, a change in ocean water chemistry also increased sulfur toxicity and depleted oxygen.

Furthermore, the team found that the timing of the mass crocodyliform extinction coincided with the origin of modern marine turtles. Their ancestors were common prey for ancient marine crocs. “This major extinction of crocodyliforms was literally a case of out with the old and in with the new for many species,”Tennant says in a statement. “Marine turtles, the gentle, graceful creatures of the sea, may have been one of the major winners from this changing of the old guard. They began to thrive in oceans around the world when their ferocious arch-predators went into terminal decline.”

However, the drop in marine croc diversity also paved the way for their ecological replacements, including sharks, plesiosaurs, and other large predators.

Read more: http://www.iflscience.com/plants-and-animals/extinction-croc-ancestors-helped-out-cretaceous-turtles

Ancient Marine Reptile May Have Hunted Bioluminescent Fish At Night

When Tyrannosaurus rex prowled the land, the oceans of the Late Cretaceous werent particularly safe either. Cruising the waters at the time were large predatory reptiles known as mosasaurs, elongated and streamlined for hunting down their prey in the warm shallow seas. Some of these were true beasts reaching up to 18 meters (59feet) in length, but others were a little more modest. Researchers have revealed the first mosasaur of its kind to be discovered in Japan, and discovered that it probably hunted at night using binocular vision.

The marine reptile in question is a species called Phosphorosaurus ponpetelegans, and came in at a relatively tiny for mosasaur at least 3 meters(10 feet) long. The remarkably well preserved skull is the only example known from Japan, and helps palaeontologists fill a geographic gap of the species from between the Middle East and the eastern Pacific. It also allows the researchers to determine that the animal quite possibly fed on bioluminescent fish and squid during the night, whilst their larger cousins dominated the sea during the daytime.

The forward-facing eyes on Phosphorosaurus provide depth perception to vision, and it’s common in birds of prey and other predatory mammals that dwell among us today, explains Takuya Konishi in a statement. Konishi is acoauthor of the study, which is published in the Journal of Systematic Palaeontology. But we knew already that most mosasaurs were pursuit predators based on what we know they preyed upon swimming animals. Paradoxically, these small mosasaurs like Phosphorosaurus were not as adept swimmers as their larger contemporaries because their flippers and tailfins weren’t as well developed.

But when compared to their larger relatives, the vision of Phosphorosaurus is markedly different. On the bigger specimens, their eyes are located on either side of their head not unlikea horse or deer today which is thought to have helped streamline the reptile and allow it to swim faster to catch the turtles, sharksand other mosasaurs they fed on.

With the smaller species, however, the eyes are forward facing, which in nocturnal animals doubles the number of photoreceptors used to detect light. Because fossils of lantern fish and squid-like animals have been found in the same rock formations in Japan as Phosphorosaurus, the researchers suggest that the reptilemight have been hunting at night. They even go on to postulate that perhaps this might have been a larger trend for other species of mosasaurs, with the larger animals hunting and chasing down prey during the day, whilethe smaller, more vulnerable ones only came out at night.

The excavation of the skull that enabled this discovery took a painstaking two years. It involveddipping the rock in which it was encased in acid overnight, and then washing it off every morning, gradually freeing the bones. These werethen pieced togetherto re-create the original skull. The researchersnow intend to look into how the species fits into the evolutionary tree of mosasaurs.

Read more: http://www.iflscience.com/plants-and-animals/ancient-marine-reptile-may-have-hunted-bioluminescent-fish-night