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Titanosaurs of the Antarctic
By Mike, December 19, 2011
Research Team Reveals Evidence of Titanosaurs Having lived in Antarctica
The discovery of a single, fossilised bone could help scientists solve a puzzle concerning the largest land animals of all time – the Sauropods. Fossils of these giant, long-necked dinosaurs have been found on every continent, except one, the land mass of Antarctica. However, a team of Argentinian scientists have unearthed evidence that one group of Sauropods – the Titanosaurs may have roamed the southernmost continent after all.
The fossil, believed to represent a portion of the dinosaur’s tail (caudal vertebra), was discovered on James Ross Island by an Argentinian-led team. The bone measures almost twenty centimeters in length and is believed to have come from the middle third of the dinosaur’s long tail. Although, it is not possible to identify the dinosaur genus from such a fragment of the skeleton, the scientists have stated that the bone probably belongs to a “lithostrotian titanosaur”. The Lithostrotia are a clade of titanosaurs (a group of anatomically and probably closely related, similar titanosaurs), which are associated with Upper Cretaceous strata from South America and Madagascar.
The discovery was first presented at a recent palaeontological conference held in Nevada, but it has just been published in the German scientific journal -Naturwissenschaften (translates as “The Science of Nature”).
Authors Dr Ignacio Alejandro Cerda, from the Conicet research institute in Argentina, and colleagues wrote:
“Our finding indicates that advanced titanosaurs achieved a global distribution at least by the Late Cretaceous.”
During the Cretaceous the super-continent of Gondwanaland in the southern hemisphere continued to break up, Antarctica had once formed part of this huge landmass along with India, Australia, South America and Africa but by about ninety million years ago, only Australia remained joined to Antarctica. As the break up continued, the land bridges that connected Antarctica to Australia became more and more tenuous until by the end of the Cretaceous, Antarctica was isolated. For much of the Cretaceous Antarctica was covered by lush, conifer and fern forests and it was much, much warmer than it is today, for this remaining part of Gondwanaland was heated as a result of ocean currents sweeping down from the equator. However, by the Late Cretaceous the climate on Antarctica had begun to change dramatically and this landmass became much colder.
The discovery of this single vertebra raises intriguing questions. For example, if there was a large, herbivorous dinosaur living on what was to become Antarctica as late as seventy million years ago (Campanian faunal stage), then the flora must have been rich enough to support such large animals. If there was a large herbivore in the ecosystem, could there have been a large, Theropod predator? Perhaps a “living fossil” such as an Allosaurid, a type of meat-eating dinosaur that had become extinct elsewhere in the world by the end of the Cretaceous but may have hung on in isolated pockets where other Theropods such as Abelisaurids or Tyrannosaurs could not reach due to the lack of land bridges.
There have been fossils of other long-necked dinosaurs found on Antarctica before, but as far as we at Everything Dinosaur know, these fossilized bones represent very primitive, early members of the Sauropoda family, know as Sauropodomorpha. An example would be the Early Jurassic Glacialisaurus which was discovered in 2007.
To read more about the discovery of this early, long-necked dinosaur: Primitive Long-necked dinosaurs from Antarctica
The authors conclude in their paper:
“Our discovery, and subsequent report, of these sauropod dinosaur remains from Antarctica improves our current knowledge of the dinosaurian faunas during the Late Cretaceous on this continent.”
The Fossilized Bone and Illustrations showing the Complete Vertebra
~20-centimeter long fossil bone reveals presence of advanced titanosaurs in Late Cretaceous Antarctica
The picture above shows the fossil bone (pictures a-c) with illustrations (d-f) showing the fossil fragments in association to the rest of the single tail bone. The fossil is actually a centrum (central, cylindrical component of a vertebra). It is the concave/convex shape of the anterior and posterior portions of the centrum that have enabled scientists to identify this fossil bone as belonging to an advanced Titanosaur from the lithostrotian clade.
The picture shows the caudal vertebra centrum viewed from the front (anterior view) in “a” and “d”; viewed from the right side (right lateral view) in “b” and “e” and finally from the rear (posterior view) in “c” and “f”.
blog.everythingdinosaur.co.uk/blog/_archives/2011/12/19/titanosaurs-of-the-antarctic.html
Titanosaur fossils unearthed on Antarctic Peninsula
Submitted by Jeffrey Serrill on December 24, 2011 - 12:52pm
Fossil evidence of an ancient sauropod, the classification which contains some of the largest animals to ever walk the earth, has recently been uncovered on the Antarctic continent by an Argentinian research team. Similar fossils have previously been observed on every other continent, and this new finding suggests that these creatures were characterized by an essentially global distribution prior to the end of the Cretaceous Period, when a massive extinction event eradicated most forms of non-avian dinosaur life.
Specifically, these fossil remnants contained an incomplete caudal vertebra, one that appears to resemble those previously attributed to titanosaurs, one of the predominant sauropodal subdivisions at the end of the Cretaceous. The titanosaur group, thought to include at least 50 different known species, is thought to include some of the heaviest dinosaurs to ever walk the Earth; these species were typically characterized by long necks and tails, small heads, and an herbivorous diet.
The fossils were found in sedimentary deposits located adjacent to the Weddell Sea, which forms the eastern boundary of the Antarctic Peninsula. This peninsula comprises the northern-most region of the continent, and has become an important area for researchers interested in climate change. As such, numerous research outposts exist there, providing a base of operations for a variety of different research projects.
In some areas of the world, including South America, titanosaurs are thought to have been the predominant herbivorous animals at the time of the post-Cretaceous cataclysm. At some point during the cretaceous period (145-65 MYA), it is believed that the Antarctic continent was connected to South America via a narrow isthmus, explaining how these apparently similar fossil remnants could exist in such geographically distant regions.
This is not the first time that fossil evidence suggesting the ancient presence of dinosaurs on the island has been discovered. In 1986, Argentinian geologists uncovered fossil evidence of Antarctopelta oliveroi, a quadrupedal herbivore with a body covered in armored plates. Coupled with a subsequent American discovery of a theropodal fossil in 2003, it is widely agreed that James Ross Island, and likely other regions of the continent, were once inhabited by a significant number of dinosaur species.
This finding provides important insight into the geographic distribution of these titanosaur species prior to the end of the Cretaceous period, and helps paleontologists fill at least one of the huge number of gaps which exist in the Antarctic fossil record.
Original Research Paper: Cerda IA et al (2011). The first record of a sauropod dinosaur from Antarctica. Naturwissenschaften – The Science of Nature. DOI 10.1007/s00114-011-0869-x
www.labgrab.com/users/jeffrey-serrill/blog/titanosaur-fossils-unearthed-antarctic-peninsula_id%3D1243
By Mike, December 19, 2011
Research Team Reveals Evidence of Titanosaurs Having lived in Antarctica
The discovery of a single, fossilised bone could help scientists solve a puzzle concerning the largest land animals of all time – the Sauropods. Fossils of these giant, long-necked dinosaurs have been found on every continent, except one, the land mass of Antarctica. However, a team of Argentinian scientists have unearthed evidence that one group of Sauropods – the Titanosaurs may have roamed the southernmost continent after all.
The fossil, believed to represent a portion of the dinosaur’s tail (caudal vertebra), was discovered on James Ross Island by an Argentinian-led team. The bone measures almost twenty centimeters in length and is believed to have come from the middle third of the dinosaur’s long tail. Although, it is not possible to identify the dinosaur genus from such a fragment of the skeleton, the scientists have stated that the bone probably belongs to a “lithostrotian titanosaur”. The Lithostrotia are a clade of titanosaurs (a group of anatomically and probably closely related, similar titanosaurs), which are associated with Upper Cretaceous strata from South America and Madagascar.
The discovery was first presented at a recent palaeontological conference held in Nevada, but it has just been published in the German scientific journal -Naturwissenschaften (translates as “The Science of Nature”).
Authors Dr Ignacio Alejandro Cerda, from the Conicet research institute in Argentina, and colleagues wrote:
“Our finding indicates that advanced titanosaurs achieved a global distribution at least by the Late Cretaceous.”
During the Cretaceous the super-continent of Gondwanaland in the southern hemisphere continued to break up, Antarctica had once formed part of this huge landmass along with India, Australia, South America and Africa but by about ninety million years ago, only Australia remained joined to Antarctica. As the break up continued, the land bridges that connected Antarctica to Australia became more and more tenuous until by the end of the Cretaceous, Antarctica was isolated. For much of the Cretaceous Antarctica was covered by lush, conifer and fern forests and it was much, much warmer than it is today, for this remaining part of Gondwanaland was heated as a result of ocean currents sweeping down from the equator. However, by the Late Cretaceous the climate on Antarctica had begun to change dramatically and this landmass became much colder.
The discovery of this single vertebra raises intriguing questions. For example, if there was a large, herbivorous dinosaur living on what was to become Antarctica as late as seventy million years ago (Campanian faunal stage), then the flora must have been rich enough to support such large animals. If there was a large herbivore in the ecosystem, could there have been a large, Theropod predator? Perhaps a “living fossil” such as an Allosaurid, a type of meat-eating dinosaur that had become extinct elsewhere in the world by the end of the Cretaceous but may have hung on in isolated pockets where other Theropods such as Abelisaurids or Tyrannosaurs could not reach due to the lack of land bridges.
There have been fossils of other long-necked dinosaurs found on Antarctica before, but as far as we at Everything Dinosaur know, these fossilized bones represent very primitive, early members of the Sauropoda family, know as Sauropodomorpha. An example would be the Early Jurassic Glacialisaurus which was discovered in 2007.
To read more about the discovery of this early, long-necked dinosaur: Primitive Long-necked dinosaurs from Antarctica
The authors conclude in their paper:
“Our discovery, and subsequent report, of these sauropod dinosaur remains from Antarctica improves our current knowledge of the dinosaurian faunas during the Late Cretaceous on this continent.”
The Fossilized Bone and Illustrations showing the Complete Vertebra
~20-centimeter long fossil bone reveals presence of advanced titanosaurs in Late Cretaceous Antarctica
The picture above shows the fossil bone (pictures a-c) with illustrations (d-f) showing the fossil fragments in association to the rest of the single tail bone. The fossil is actually a centrum (central, cylindrical component of a vertebra). It is the concave/convex shape of the anterior and posterior portions of the centrum that have enabled scientists to identify this fossil bone as belonging to an advanced Titanosaur from the lithostrotian clade.
The picture shows the caudal vertebra centrum viewed from the front (anterior view) in “a” and “d”; viewed from the right side (right lateral view) in “b” and “e” and finally from the rear (posterior view) in “c” and “f”.
blog.everythingdinosaur.co.uk/blog/_archives/2011/12/19/titanosaurs-of-the-antarctic.html
Titanosaur fossils unearthed on Antarctic Peninsula
Submitted by Jeffrey Serrill on December 24, 2011 - 12:52pm
Fossil evidence of an ancient sauropod, the classification which contains some of the largest animals to ever walk the earth, has recently been uncovered on the Antarctic continent by an Argentinian research team. Similar fossils have previously been observed on every other continent, and this new finding suggests that these creatures were characterized by an essentially global distribution prior to the end of the Cretaceous Period, when a massive extinction event eradicated most forms of non-avian dinosaur life.
Specifically, these fossil remnants contained an incomplete caudal vertebra, one that appears to resemble those previously attributed to titanosaurs, one of the predominant sauropodal subdivisions at the end of the Cretaceous. The titanosaur group, thought to include at least 50 different known species, is thought to include some of the heaviest dinosaurs to ever walk the Earth; these species were typically characterized by long necks and tails, small heads, and an herbivorous diet.
The fossils were found in sedimentary deposits located adjacent to the Weddell Sea, which forms the eastern boundary of the Antarctic Peninsula. This peninsula comprises the northern-most region of the continent, and has become an important area for researchers interested in climate change. As such, numerous research outposts exist there, providing a base of operations for a variety of different research projects.
In some areas of the world, including South America, titanosaurs are thought to have been the predominant herbivorous animals at the time of the post-Cretaceous cataclysm. At some point during the cretaceous period (145-65 MYA), it is believed that the Antarctic continent was connected to South America via a narrow isthmus, explaining how these apparently similar fossil remnants could exist in such geographically distant regions.
This is not the first time that fossil evidence suggesting the ancient presence of dinosaurs on the island has been discovered. In 1986, Argentinian geologists uncovered fossil evidence of Antarctopelta oliveroi, a quadrupedal herbivore with a body covered in armored plates. Coupled with a subsequent American discovery of a theropodal fossil in 2003, it is widely agreed that James Ross Island, and likely other regions of the continent, were once inhabited by a significant number of dinosaur species.
This finding provides important insight into the geographic distribution of these titanosaur species prior to the end of the Cretaceous period, and helps paleontologists fill at least one of the huge number of gaps which exist in the Antarctic fossil record.
Original Research Paper: Cerda IA et al (2011). The first record of a sauropod dinosaur from Antarctica. Naturwissenschaften – The Science of Nature. DOI 10.1007/s00114-011-0869-x
www.labgrab.com/users/jeffrey-serrill/blog/titanosaur-fossils-unearthed-antarctic-peninsula_id%3D1243
