Jan. 30, 2013 ? A cluster of tapeworm eggs discovered in 270-million-year-old fossilized shark feces suggests that intestinal parasites in vertebrates are much older than previously known, according to research published Jan. 30 in the open access journal PLOS ONE by Paula Dentzien-Dias and colleagues from the Federal University of Rio Grande, Brazil.
Remains of such parasites in vertebrates from this era are rare- of 500 samples examined, only one revealed the tapeworm eggs. This particular discovery helps establish a timeline for the evolution of present-day parasitic tapeworms that occur in foods like pork, fish and beef.
The fossilized eggs were found in a cluster very similar to those laid by modern tapeworms. Some of them are un-hatched and one contains what appears to be a developing larva. According to the study, "This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was previously known and occurred at least 270-300 million years ago."
The fossil described in this study is from Middle-Late Permian times, a period followed by the largest mass extinction known, when nearly 90% of marine species and 70% of terrestrial species died out.
Financial support was provided by the Conselho Nacional de Desenvolvimento Cient?fico e Tecnologico -- Brazil (CNPq) through a study grant (PCD-D, AEQF and BH) and the Project 478914/2006-7 (Edital MCT/CNPq 02/2006 -- Universal). This work was also partially funded by the Conselho Nacional de Desenvolvimento Cient?fico e Tecnologico through scholarships granted to AEQF, BH and CLS.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Story Source:
The above story is reprinted from materials provided by Public Library of Science.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal Reference:
- Paula C. Dentzien-Dias, George Poinar, Ana Emilia Q. de Figueiredo, Ana Carolina L. Pacheco, Bruno L. D. Horn, Cesar L. Schultz. Tapeworm Eggs in a 270 Million-Year-Old Shark Coprolite. PLoS ONE, 2013; 8 (1): e55007 DOI: 10.1371/journal.pone.0055007
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
Source: http://feeds.sciencedaily.com/~r/sciencedaily/strange_science/~3/HjidAyIfjJ0/130130184200.htm
there will be blood nigel barker 420 secret service fenway park philadelphia flyers 4/20
কোন মন্তব্য নেই:
একটি মন্তব্য পোস্ট করুন