Newly described trilobite genera and species alter one morphological character to overcome challenges and modify another character to fulfill the original function, presenting a unique example of functional change in an animal.
Silurian trilobites Waukesha Aspis Atonaefrom the Silurian Waukesha biota of Wisconsin, USA. Image credit: Kenneth Gass, specimen is University of Wisconsin Geology Museum.
of trilobite, Waukesha Aspis Atonaefrom marine strata. Silurian (437 meters) Waukesha biota of Wisconsin.
It is the only trilobite found in abundance in this biota and is primarily known for its diversity and exceptional state of conservation. arthropod and insect-like animals.
researcher Dr. Enrique Alberto Randolph and Kenneth C. Gass This trilobite is described in their book new paper in paleontology journal.
The family that includes this trilobite usually has a pair of spines (sexual spines), one on each side (left and right) of the head shield (head).
There is also a tail (pygidium) that usually reaches a point on the back and is usually extended to form the medial vertebrae (caudal vertebrae). This spine is very long and probably helps turn the animal over if necessary.
In contrast, Pygidium Waukesha Spis It lacks a caudal spine and has a depression (bay) in its place, which is highly unusual for Silurian members of this family.
Therefore, this depression does not serve to turn the animal over, but may have enhanced breathing while the animal was in the registration position by maintaining an opening for water to flow into the gills of the trilobite.
What is even more distinctive is that the genus spines of this species are extremely long, reaching up to the pygidium. These may have worked well to turn the animal over.
Other features Waukesha Aspis Atonae Of note is the significant clustering of individuals, with some cases containing up to 49 partial or complete exoskeletons, likely due to physiological tolerance in the habitat and in the reserve. This may be due to classification and storage in storage locations. gastrointestinal (intestinal) tract occurring only in a few other trilobite species.
“This trilobite is important because it allows us to learn more about the functional morphology of the family (Dharmaceae), typically a conservative group,” Dr. Randolph said.
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E. Randolph and K. Gass. 2024. Waukesha Aspis Atonae n. generation. n. sp.: A specialized Dharmaniidae (trilobite) from the Terikians of southeastern Wisconsin. paleontology journalp. 1-9; doi: 10.1017/jpa.2024.32
Source: www.sci.news
