A Dutch scientist has discovered a giant crab in New Zealand

With a claw of about 20 (!) centimeters, the crab – which lived about 8.8 million years ago – is in a class of its own.

Researchers, including a University of Utrecht scientist, write this New Zealand Journal of Geology and Geophysics. Their study was about a fossil crab found on a beach in New Zealand's North Island. “I'm constantly researching fossil crabs that are new or interesting to science,” says researcher Barry Van Backel. Scientias.nl. “But a fossil crab this large is unique.”

Very large
Fossil remains reveal that the crab had scissors about 20 centimeters long. His armor was still a bit larger. According to Bacall, that makes the crab 'extremely large', at least compared to other fossil crabs. Crab is a bit less impressive considering its only pedigree. Because it could get even bigger, says van Backel. “Its modern cousin, the Giant Southern Crab Or the Tasmanian giant crab, which grows at least twice as big! We think this fossil ancestor may have grown large as well, but we're waiting for more material to be found.

New species
Pending further material and research, scientists can conclude that the fossil giant crab belongs to a previously undescribed species. Researchers have named it Pseudocarcinus Karlrappenheimeri data.

Unique
It is quite unique that the researchers were able to describe the new species. “First of all, these (crabs, ed.) don't easily fossilize completely, but our encounter with this group in New Zealand was unexpected.” This is how Ann lives B. Karl Rappenheimer The related Tasmanian crab is found only in Australian waters.

habitat
In addition B. Karl Rappenheimer Of course its size is unique. “The scale is unique and requires special circumstances,” says Van Backel. Therefore, such giant crabs need some food and minerals in the water. Water should also have a certain temperature. “It's a precise combination that doesn't occur almost anywhere else.” But it looks like 8.8 million years ago B. Karl Rappenheimer Now near the North Island of New Zealand, everything was so orderly as to reach the great size before mentioned. “Its habitat, which we explored and reconstructed, is unique,” says van Backel. “Millions of years before this crab lived, a chain of volcanoes spread a lot of volcanic material (ash) under the sea. There was a lot of gas under the sea. These high-altitude, hot, nutrient-rich waters formed 'volcanic tubes' where shells, snails and small crabs and hermits lived. A small fauna appeared with the crabs and they prepared the menu B. Karl Rappenheimer. “He tore these animals apart with the strong 'teeth' of his great scissors.”

Impacts
The research by van Beckel and colleague Alex Osso not only resulted in the description of a new species. But in a more detailed description of the ecosystem he was a part of. “We know a unique ecological community from prehistoric New Zealand,” says Van Backel. In addition, the research provides further insight into the history of the giant crab species. Pseudocarcinus. “The geological history of this special group of giant crabs has become clear at once.”

It's doubtful that scientists could expect to make these kinds of meaningful discoveries in New Zealand, so that makes the work of Van Backel and colleagues all the more unique. “We suspect that these giant crabs – typically large crabs in New Zealand – went extinct after the Miocene. Volcanic inactivity and migration away from Australia changed the environment significantly. So I expect new discoveries in Australia soon.