Showing posts with label Nevada desert. Show all posts
Showing posts with label Nevada desert. Show all posts

Monday, 1 September 2014

Climate change puts endangered Devils Hole pupfish at risk of extinction

28th August 2014

Death Valley Pupfish spawning in Salt Creek.jpgClimate change is hurting reproduction of the endangered Devils Hole pupfish, threatening the survival of this rare species that has numbered as few as 35 individuals, new research by the University of Nevada, Reno and Desert Research Institute shows.
Scientists report that geothermal water on a small shelf near the surface of an isolated cavern in the Nevada desert where the pupfish live is heating up as a result of climate change and is likely to continue heating to dangerous levels.

The hotter water, which now reaches more than 93 degrees, has shortened by one week the amount of time pupfish larvae have to hatch during the optimal recruitment periods. The recruitment period is the 10 weeks during which water temperatures are conducive to egg hatching and sufficient food is available to sustain the newly hatched larvae. This decrease contributed to the decline of the adult pupfish population, according to a scientific paper published in Water Resources Research, a journal of the American Geophysical Union.





Sunday, 13 January 2013

Giant Fossil Predator Provides Insights Into the Rise of Modern Marine Ecosystem Structures


Jan. 7, 2013 — An international team of scientists has described a fossil marine predator measuring 8.6 meters in length (about 28 feet) recovered from the Nevada desert in 2010 as representing the first top predator in marine food chains feeding on prey similar to its own size.

A paper with their description will appear the week of Jan. 7, 2013 in the early electronic issue of Proceedings of the National Academy of Sciences.

Scientists who studied the fossil include lead author Dr. Nadia Fröbisch and Prof. Jörg Fröbisch (both at Museum für Naturkunde Leibniz-Institut für Evolutions- und Biodiversitätsforschung), Prof. P. Martin Sander (Steinmann Institute of Geology, Mineralogy, and Paleontology, Division of Paleontology, University of Bonn), Prof. Lars Schmitz (W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, California) and Dr. Olivier Rieppel (The Field Museum, Chicago, Illinois).

The 244-million-year-old fossil, named Thalattoarchon saurophagis (lizard-eating sovereign of the sea) is an early representative of the ichthyosaurs, a group of marine reptiles that lived at the same time as dinosaurs and roamed the oceans for 160 million years. It had a massive skull and jaws armed with large teeth with cutting edges used to seize and slice through other marine reptiles in the Triassic seas. Because it was a meta-predator, capable of feeding on animals with bodies similar in size to its own, Thalattoarchon was comparable to modern orca whales.

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