Page 77 - Introduction to Paleobiology and The Fossil Record

64 INTRODUCTION TO PALEOBIOLOGY AND THE FOSSIL RECORD

Box 3.1 Exceptional preservation of muscle and microbes

There are now many examples of fossil animals with muscle tissue preserved. These range in age
right back to the Cambrian, and there is no diminution in the quality of the specimens with geologic
age. A good example is the report of a horseshoe crab from the Upper Jurassic of Germany, presented
by Derek Briggs and colleagues (2005) from Yale University and the University of Bristol. The speci-
men of Mesolimulus walchi (Fig. 3.4a) from the Plattenkalk at Nusplingen in Baden-Württemberg

(b)

(a)

(c)

(d)
Figure 3.4 Exceptional preservation of muscle in the Jurassic horseshoe crab Mesolimulus walchi:
(a) the whole specimen showing the rounded headshield (prosoma), with preserved muscle tissues

in the middle; (b) muscle fibers; (c) banding across muscle fibers revealed by early decay; and (d)

small coccoid microbes associated with the muscle fibers. Scale bars: 20 mm (a), 50 μm (b),
10 μm (c, d). (Courtesy of Derek Briggs.)