This image shows the trilobite in two pieces: part of the head and thorax/back. Maybe it was a molt. See this link for different picture of this same specimen: http://www.kyanageo.org/Fossils/silurian/arthropoda/trimerus_delphinocephalus.jpg
Here is a link that shows another from the same area but it appears fully intact: http://weekstrilobites.com/Trimerus.htm
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