A toothy grin only a palaeontologist could love
McGill and University of São Paulo researchers identify new species of 70-million-year-old crocodile - with really big teeth and dog-shaped head.
To McGill palaeontology professor Hans Larsson, his graduate student Felipe Montefeltro and Professor Max Langer of the University of Sao Paulo, a recently discovered crocodile fossil head looks like a dog. To the rest of us - as well as croc's prey of the day - it looks like a ferocious toothy nightmare.
Named Pissarrachampsa sera, the fossil was discovered by a municipal worker in 70-million-year-old Cretaceous sediments in a small town in Minas Gerais, Brazil.
"Whereas modern-day amphibious crocodiles have low and flat heads, this new find gives
us one of the first detailed insights into the head anatomy of this weird group of extinct
crocs called Baurusuchia that feature tall, dog-like skulls with enlarged canines, and long-
limbed body proportions," said Larsson.
us one of the first detailed insights into the head anatomy of this weird group of extinct
crocs called Baurusuchia that feature tall, dog-like skulls with enlarged canines, and long-
limbed body proportions," said Larsson.
Their ecology was probably similar to that of wild dogs living today. Given the number and
size of their teeth, the researchers believe these carnivorous crocs fed on animals of the
same 15- to 20-foot size range - that is dinosaurs and fellow crocs from the region. They
would have used relatively stereoscopic vision to track prey and, rather than scramble like
the crocs we see today, they galloped on elongated limbs.
size of their teeth, the researchers believe these carnivorous crocs fed on animals of the
same 15- to 20-foot size range - that is dinosaurs and fellow crocs from the region. They
would have used relatively stereoscopic vision to track prey and, rather than scramble like
the crocs we see today, they galloped on elongated limbs.
A sketch by Larsson imagines how this newly discovered species would have appeared in
predatory motion. Though the body might seem more dinosaur in shape than today's
crocodile, the fossil head carries the definitive characteristics of crocodiles from that era,
including a well-developed secondary palate, socketed teeth, advanced cranial air spaces,
roughened bone surfaces, plated armour, and massive attachments for jaw closing muscles.
predatory motion. Though the body might seem more dinosaur in shape than today's
crocodile, the fossil head carries the definitive characteristics of crocodiles from that era,
including a well-developed secondary palate, socketed teeth, advanced cranial air spaces,
roughened bone surfaces, plated armour, and massive attachments for jaw closing muscles.
Recent CT scans are offering more fascinating aspects of the fossil, such as its brain size
and shape and hearing abilities. Baurusuchian crocs are characterized by a significant
number of unique anatomical features such as low tooth counts, tall, thin skulls, forward
facing nostrils, and derived jaw-closing muscle attachments. After comparing the new
species to other Baurusuchids and their relatives, the researchers noticed large gaps on
either side of the fossil's morphology.
and shape and hearing abilities. Baurusuchian crocs are characterized by a significant
number of unique anatomical features such as low tooth counts, tall, thin skulls, forward
facing nostrils, and derived jaw-closing muscle attachments. After comparing the new
species to other Baurusuchids and their relatives, the researchers noticed large gaps on
either side of the fossil's morphology.
"We are dealing with an exceptionally divergent lineage of extinct crocodile diversity. There
are many fossils that still need to be found to link this crocodile to those who came before
and after," said Montefeltro.
are many fossils that still need to be found to link this crocodile to those who came before
and after," said Montefeltro.
Montefeltro explained that the name of this new member of the croc family pays homage
to the location of the fossil's discovery. Piçarra is a regional word for sandstone and
Champsa is a Latinization of the Greek word for crocodile. Sera, is Latin for late - which
refers to both the circumstances in which the fossil was found, that is, it was almost left
behind in a 2008 expedition because of a tight schedule and, the Minas Gerais state flag
that quotes Virgil "Libertas Quæ Sera Tamen" meaning "Freedom, Albeit Late."
to the location of the fossil's discovery. Piçarra is a regional word for sandstone and
Champsa is a Latinization of the Greek word for crocodile. Sera, is Latin for late - which
refers to both the circumstances in which the fossil was found, that is, it was almost left
behind in a 2008 expedition because of a tight schedule and, the Minas Gerais state flag
that quotes Virgil "Libertas Quæ Sera Tamen" meaning "Freedom, Albeit Late."
Though their importance for crocodyliform evolution is widely recognized, there are still a
lot of questions about the internal relationships of the group not yet studied, but which all
three researchers plan to explore. A digital reconstruction of the fossil's brain cavity is in
the works and will be presented later this fall at the Society of Vertebrate Paleontology's
annual meeting.
Autor; McGill Reporter
lot of questions about the internal relationships of the group not yet studied, but which all
three researchers plan to explore. A digital reconstruction of the fossil's brain cavity is in
the works and will be presented later this fall at the Society of Vertebrate Paleontology's
annual meeting.
Autor; McGill Reporter
Additional information:
Felipe C. Montefeltro is a PhD Candidate at the Faculdade de Filosofia Ciências e Letras
de Ribeirão Preto, Universidade de São Paulo (FFCLRP-USP), Brazil, working on evolution
of Crocodyliformes. He is completing his studies as an exchange student at the Redpath
Museum of McGill University.
de Ribeirão Preto, Universidade de São Paulo (FFCLRP-USP), Brazil, working on evolution
of Crocodyliformes. He is completing his studies as an exchange student at the Redpath
Museum of McGill University.
Hans C. E. Larsson is an Associate Professor and Canada Research Chair in Vertebrate
Paleontology at the Redpath Museum, McGill University He is an expert in crocodyliform
evolution and is supervising Mr. Montefeltro at McGill.
Paleontology at the Redpath Museum, McGill University He is an expert in crocodyliform
evolution and is supervising Mr. Montefeltro at McGill.
Max C. Langer is a Professor at Faculdade de Filosofia Ciências e Letras de Ribeirão Preto,
Universidade de São Paulo and expert on Brazilian archosaurs. He is supervising
Mr. Montefeltro at USP.
Universidade de São Paulo and expert on Brazilian archosaurs. He is supervising
Mr. Montefeltro at USP.
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