Blog Pick of the Month – May 2010
May 2010 just ended, so it’s time for the PLoS ONE Blog Pick Of The Month.
There were 30 blog posts covering PLoS ONE articles aggregated on ResearchBlogging.org in May. As usual, a number of posts were excellent so it took me a lot of time and effort to narrow down the field and finally choose just one. So, drumroll, please….
…the winner for this month is Brian Switek of Laelaps. His post, Off the prehistoric coast of Panama, a mega-toothed shark nursery describes the work in the PLoS ONE article Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama by Catalina Pimiento, Dana J. Ehret, Bruce J. MacFadden and Gordon Hubbell. From the Abstract:
As we know from modern species, nursery areas are essential shark habitats for vulnerable young. Nurseries are typically highly productive, shallow-water habitats that are characterized by the presence of juveniles and neonates. It has been suggested that in these areas, sharks can find ample food resources and protection from predators. Based on the fossil record, we know that the extinct Carcharocles megalodon was the biggest shark that ever lived. Previous proposed paleo-nursery areas for this species were based on the anecdotal presence of juvenile fossil teeth accompanied by fossil marine mammals. We now present the first definitive evidence of ancient nurseries for C. megalodon from the late Miocene of Panama, about 10 million years ago.
We collected and measured fossil shark teeth of C. megalodon, within the highly productive, shallow marine Gatun Formation from the Miocene of Panama. Surprisingly, and in contrast to other fossil accumulations, the majority of the teeth from Gatun are very small. Here we compare the tooth sizes from the Gatun with specimens from different, but analogous localities. In addition we calculate the total length of the individuals found in Gatun. These comparisons and estimates suggest that the small size of Gatun’s C. megalodon is neither related to a small population of this species nor the tooth position within the jaw. Thus, the individuals from Gatun were mostly juveniles and neonates, with estimated body lengths between 2 and 10.5 meters.
We propose that the Miocene Gatun Formation represents the first documented paleo-nursery area for C. megalodon from the Neotropics, and one of the few recorded in the fossil record for an extinct selachian. We therefore show that sharks have used nursery areas at least for 10 millions of years as an adaptive strategy during their life histories.
My early elementary reading school choices often got me into trouble. Every week I would pass over the recommended, grade-appropriate sections for the few shelves containing the books about dinosaurs, sharks, and alligators – if it was big and hard sharp teeth, I wanted to learn about it. The school librarian was not too pleased with this, even calling my parents in on one occasion to insist that I read something fit for younger children, but I just could not get enough of theropods, crocodylians, and enormous sharks.
Given my love for “cold-blooded killers” (as so many titles described them) it was not very long before I learned about “Megalodon” (formally known as Carcharocles megalodon), an immense shark which disappeared just a million-and-a-half years before human bathers began to wade into the shallows. Perhaps, some books hinted, the giant sharks still lurked in some unknown ocean recess, and a photograph of an array of American Museum of Natural History scientists inside the restored jaws of the shark drove home the point that it could have made of meal of just about anything it wanted. It was one of the most fascinating and terrifying images I had ever seen…
And there Brian jumps into the fascinating science of this paper!
I am about to notify both Brian and the authors of the article and send them the famous PLoS ONE t-shirts as prizes. This month’s runners-up are Darren Naish of Tetrapod Zoology, Daemios from Rudimenthos and Neuroskeptic of the Neuroskeptic blog.
March 2009: Ed Yong
April 2009: Eric Michael Johnson
May 2009: Christie Wilcox
June 2009: Iddo Friedberg
July 2009: Toaster Sunshine and Hermitage
August 2009: Bjoern Brembs
September 2009: Alun Salt
October 2009: Andrew Farke
November 2009: John Beetham
December 2009: SciCurious
January 2010: Anne-Marie Hodge
February 2010: Princess Ojiaku
March 2010: Grrrlscientist
April 2010: Jason Goldman