At the end of the school day, I saw something hanging/dropping from the tree outside our classroom window. It seemed to behave (from a distance) like a spider, but it looked like an acorn. I went out and located the spider in the grass. All the school children had to see it . . . and now we need to know what this creature is!
If it were on top of a quarter, its legs would hang over the edge, but its body isn't quite as big as a penny. Could it be a pregnant spider?
This is an orb-weaving spider (family Araneidae) in the genus Araneus. It most lilely is Araneus diadematus (see http://www.ivory.org/spiders/araneus.diadematus.html), but some individuals of Araneus trifolium can have a similar color pattern (see http://www.spiderzrule.com/shamrock.htm - this spider is extremely variable in coloration). All are harmless to humans.
