Miocene Spider Fossil from Nevada
Chelicerata, Class Arachnida, Order Araneae
fossil is 12 mm in length
Spider fossils are relatively rare in the fossil record since the
chitinous exoskeleton poorly preserves. This one comes from central
Nevada shales that offer some of the best-preserved insects and
plants to be found anywhere in the world. This is a positive and
negative specimen. The abdomen is faintly in preserved, though under
close observation with a hand lens, or, microscope, much detail
is present. All eight legs, feeding appendages and head are preserved.
Nevada once had a much wetter and more temperate climate back in
the Miocene. There were many more lakes in what is now the driest
state in the USA. The Sierra uplift dramatically changed the climate
and rainfall in the state.
fossil pictures to enlarge