Trilobiten.de

[Jens]

Hier eine Arbeit zum Thema der Unterscheidung von Männlein und Weiblein bei Trilobiten. Bruttaschen bei Trilobiten sind allerdings selten vorhanden.


Richard A. Fortey, and Nigel C. Hughes (1998): Brood pouches in trilobites. - Journal of Paleontology, 72 (4): 638-649


During the Cambrian and Ordovician trilobites belonging to a variety of clades developed distinctive inflated bulbs on the preglabellar field. We make the case that these bulbs were brood pouches, which were employed for retaining and protecting larva trilobites in order to ensure a higher rate of survivorship. Living arthropods of several classes develop comparable spherical structures--for example the domicilium of certain ostracodes. Living limuloids, likely the trilobites' closest living relatives, carry large and yolky eggs in an homologous, prelabral site. There are some trilobite examples where "species pairs" found in the same fossil sites appear to differ only in the presence or absence of the preglabellar bulb. These may represent the female and male of a single species, respectively. If so, this is the first well-supported case of sexual dimorphism in trilobites. Some more problematic examples are discussed, where alleged dimorphism would have to be more extreme.

[afen123]

I guess the chinese trilobites 'Drepanura premesnili' and the 'Damesella Walcott' maybe the same species, because the rock can be seen the two trilobites together , the shield pieces broken the same way, the pygidium of the Drepanura premesnili has two big spines,maybe the male type and the Damesella has no big spines,maybe the female type.
_________________
Ich bin Fossilier