I've attached a pdf with 4 ostracod photos. The sample comes from an "ostracod ironstone", thought to be Early Paleozoic, Mackenzie Mountains, western Northwest Territories Canada. The nesting is the curiosity. Thanks.
Hello Terry,
I have never come across this in my material, first impression seems to be sedimentological winnowing and sorting, but here are a couple of papers that spring to mind that might be of interest... I don't think that these fit your case however, as they are the wrong way round; youngest outside, yours are youngest inside. Nice photos.
Article Ankumia van Veen, 1932 (nomen dubium): pathological moult re...
Article Morphology and affinities of Eridostracina: Palaeozoic ostra...
Terry,
In the most striking example of nesting I notice that there there appears to be fine clastic sediment between each molt stage. The main set of nested valves in the previous set may be in opposite orientation to the largest one. Also, if you look at all of the material, most of it is not nested. It suggests to me that sometimes the valves are moved around a bit and they, occasionally, just fit together.
I completely agree. This is the result of the mechanical movement of individual shells. All the shells are disconnected (No fusion) and therefore the rate of sedimentation was low.
- Badges
- Science topic
- Similar topics
- Agriculture