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Article Link: http://www.sci-news.com/paleontology/origolestes-lii-07880.html Enjoy!

This great question from Auspex a couple years ago can now be answered in the affirmative. Up until now there have been a few close calls but nothing conclusive. The earliest reference to alleged trilobite eggs was made by Joachim Barrande in 1872. C.D. Walcott also published a brief paper in 1877 and each of these were subsequently disproved by Percy Raymond in 1931. Zhang and Pratt 1994 also reported on possible eodiscid embryos but had to concede that they may have been produced by another soft-bodied arthropod. Now at long last we finally have what appear to be bona fide trilobite eggs. Not surprisingly, the remarkable preservation of pyritized Triarthrus specimens from New York have yielded this highly anticipated fossil gold. Pun intended, Enjoy! PYRITIZED IN SITU TRILOBITE EGGS FROM THE ORDOVICIAN OF NEW YORK (LORRAINE GROUPE): IMPLICATIONS FOR TRILOBITE REPRODUCTIVE BIOLOGY Hegna, Thomas, Martin, Markus, Soriano, Carmen (2015) Geological Society of America - North-Central Section - 49th Annual Meeting (May 19-20) Paper No. 20-3 - Presentation Time: 8:45 AM Despite a plethora of exceptionally preserved trilobites, trilobite reproduction has remained a mystery. No trilobite has preserved unambiguous eggs or genitalia. This study reports on the first occurrence of preserved, in situ trilobite eggs from Triarthrus eatoni from the Lorraine Group in upstate New York. Like other exceptionally preserved trilobites from the Lorraine Group, the trilobites are replaced with pyrite on their exoskeletons and ventral appendages. The eggs (presumably representing unfertilized eggs) are spherical to elliptical in shape, about 50 µm in size, and are clustered in the genal area of the cephalon near the lateral border. The eggs are only visible ventrally with no dorsal brood pouch or recognized sexual dimorphism. This location is consistent with how modern horseshoe crabs carry their unfertilized eggs. Trilobites likely released their gametes (eggs and sperm) through a genitalia pore of as-yet unknown location (likely near the posterior boundary of the head). If T. eatoni’s reproductive biology is representative of other trilobites, they spawned rather than mated and exhibited r-strategy reproduction. A more detailed view of the anatomy associated with the eggs in currently in progress with synchrotron x-ray tomography. Barrande, Joachim (1872) Systême Silurien du centre de la Bohême. 1 ère Partie. Recherches paléontologiques, Supplement au Vol.I: Trilobites, Crustaces divers et Poissons, (Prague and Paris) Walcott, C.D. (1877) Note on the Eggs of the Trilobite. Annual Report of the New York State Museum of Natural History, 31:66-67 Raymond, P.E. (1931) Capsule-shaped "Eggs" In: Notes on invertebrate fossils, with descriptions of new species. Bulletin of the Museum of Comparative Zoology, 55:165-213 Zhang, X.G., & Pratt, B.R. (1994) Middle Cambrian arthropod embryos with blastomeres. Science, 266:637-639