Don: There are fossil aestivation chambers in Paraguay (from the early Pleistocene), a fossil cocoon from Ontario (from the early Holocene). The Burgess shales do not have earthworm fossils, since the earliest known terrestrial earthworms are from the Carboniferous period (350 million ybp, Burgess shale, 500 million ybp). There are fossil earthworm traces from the Jurassic.
All told, and not surprisingly, there are not a lot of earthworm fossils. Lee DON BERTOLETTE wrote: > Lee- > No fossilized earthworms, not even in the Burgess shale? How about in > rest of world? > -Don > > > Date: Fri, 7 Aug 2009 13:21:39 -0500 > > From: [email protected] > > To: [email protected] > > Subject: [ENTS] Re: earthworms and invasive plants > > > > > > Don: > > > > No, they don't leave any direct traces that we know of in the > > sedimentary record. However, they do cause chemical and erosional > > changes in the soil that might show up in the sedimentation process. If > > so, no one has worked it out yet. It is also possible that some > > earthworms could be preserved in sediments as macrofossils--we have > tree > > leaves that a several million years old, so the same could happen to > > earthworms, but no one has uncovered such fossils for the glaciated > > parts of North America. > > > > Lee > > > > DON BERTOLETTE wrote: > > > Lee- > > > Yeah, I guess it's not like earthworms leave much in the way of > > > skeletal remains...is there anything in their innards that their > > > remains or 'castings' might yield identifying signatures? > > > -Don > > > > > > > Date: Fri, 7 Aug 2009 09:51:38 -0500 > > > > From: [email protected] > > > > To: [email protected] > > > > Subject: [ENTS] Re: earthworms and invasive plants > > > > > > > > > > > > Joe: > > > > > > > > Much of the earthworm literature states that earthworms were removed > > > > from the northern states by glaciers and that the worms never > returned, > > > > and/or that North American species of earthworms can't live in > > > glaciated > > > > areas. > > > > > > > > However, there is no evidence for those statements. I have never > seen > > > > any proof that earthworms lived in the north prior to the last > > > > glaciation, or that it takes more than 12,000 years for the > earthworms > > > > to move about 1200 miles from the areas where they would have lived > > > > during the peak of glaciation, to places like MA, NH and MN. So, I > > > think > > > > that they essentially reached the limit imposed by colder > climates as > > > > they moved north. > > > > > > > > The correlations between whether an area is glaciated and native > > > > earthworms are present also does not hold up very well. > Southwestern > > > WI, > > > > for example, was not glaciated and has no native earthworm, whereas > > > > Southeastern WI was glaciated and does have two species of native > > > > earthworms. In addition to that, tundra and boreal forest with > > > > permafrost would have extended as far south as TN and NC at the > peak of > > > > the last glaciation, and no North American earthworm species > would find > > > > those habitats suitable, so they had to move a great distance > just to > > > > make it back to places like MA and WI. I think earthworm > ecologists are > > > > not very good paleoecologists, and look at the world as static, > leading > > > > to their misinterpretation of glaciation versus earthworm presence. > > > > > > > > Lee > > > > > > > > J > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
