One topic in Paleontology that no Geologist was likely to have missed in school was the study of Trace fossils or Ichnofossils: geological record of biological activity (burrows, tracks, trails, borings) rather than the remains of the organism itself. Apart from help us understand the behaviour of these ancient organisms that left them they also can be used to determine the kind of environmental conditions at the time of deposition of a sedimentary rock (Tidal, Beach, River etc.). Recognizing and describing trace fossils is therefore an important part of the description of rock outcrops.
By nature trace fossils are not as easily well preserved as body fossils and find one in good condition is always a surprise. In a sand quarry on the outskirts of Orlu town (Imo state) along the road from Urualla there are very well preserved Ophiomorpha burrows ( a name or Ichnotaxon given to certain burrows interpreted to have been made in a nearshore environment).
The sands are part of the Nanka Formation, deposited in a tidally influenced estuarine precursor of the current Niger Delta in the later part of the Eocene Epoch (56-33.9 million years ago) by probably Crustaceans.
These pictures were taken almost 2 years ago. Being a sand quarry they most like have been long destroyed. The quarrying would probably have exposed more of these well preserved burrows.
Now you know what Ophiomorpha burrows actually look like.