Erik Jarvik - Work On Eusthenopteron

Work On Eusthenopteron

In particular, he conducted detailed anatomical studies of the cranium of Eusthenopteron foordi using a serial-section technique introduced by William Johnson Sollas and applied to fossil fishes by Erik Stensiö. A fossil of limited external quality was sectioned by grinding off a thin section, photographing the grind-off end and repeat the process until the whole fossil was worked through. The internal structures would then show up on long series of photographs. Working in the day before computer simulations, models was made by projecting reversal film on a board, and cut thin wax plates to match. The sticky wax plates could then be assembled to a 3 dimensional scaled up model of the skull, complete with internal structures such as nerve channels and other internal hollows rarely seen in fossils. Further section to the cranium could easily be made by cutting the wax model at the desired angle. Due to the sticky nature of the wax used, a sectioned skull was put back together by simply pressing the two sections back together. This technique was also applied to the cranium of the porolepiform Glyptolepis groenlandica.