The giant crabs of primeval times had a complex social behavior. These so-called trilobites peeled together in large groups and also met at mating season, researchers have found in the study of fossils in Portugal. A similar behavior also show the horseshoe crabs still alive today? distant relatives of the trilobites. Among the fossils, researchers also uncovered the largest specimen ever found, measuring ninety centimeters, as reported by Juan Gutiérres-Marco of the Universidad Complutense in Madrid and his colleagues. Trilobites are prehistoric crabs and are distantly related to today's cancers. They populated the seas for about 300 million years and died about 250 million years ago. Remains of trilobites are among the most important fossils in paleontology. They provide researchers with information on the development of arthropods, which today include spiders, crabs and insects. In addition, paleontologists use them as guiding fossils to determine the age of rocks. To date, more than 15, 000 trilobite species have been described.
The researchers found in the Portuguese rock accumulations of more than 1, 000 cancers. Among them were both complete animals and remnants of molting. From this, the researchers concluded that the animals lived sociably and came together for moulting. Since the molting is controlled by hormones that also play a role in reproduction, the trilobites probably also gathered at mating season. Among the fossils was a 21-centimeter-long tail shield, the carrier was a total of ninety inches long, the researchers estimated. The largest trilobite ever found was 72 inches long.
Juan Gutiérres-Marco (Universidad Complutense, Madrid) et al .: Geology, Vol. 37, p. 443 doi: 10.1130 / G25513A.1 ddp / science.de? Bele Boedding House