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Bothriolepis canadensis
Three specimens of a Devonian armored fish, fossilized together. What is preserved are the armored head and the fins of the fish, still articulated. The fish must have died together, are found in close proximity, and are exceptionally well preserved. Slab (about 20 cm in size) on display at the Field Museum of Natural History, Chicago.
Cardipeltis bryanti
This is a specimen (several cm in size) of a fossil jawless fish, from the Devonian of Wyoming, on display at the Field Museum of Natural History, Chicago. Several groups of fish (like the ostracoderms, to which this fish belongs) appear suddenly in the rock record, without many intermediates.
Cephalaspis
Entire groups of fish found as fossils in Devonian rock layers disappear from higher strata. Among them are osteostracans, like Cephalaspis, a jawless armored fish. Human fingernail for scale. Specimen on display at the Colorado Museum of Nature and Science.
Dastilbe crandalli
A fossilized example of predation. This Cretaceous fish from the Crato Formation of the Araripe Basin, Brazil, died while ingesting another fish. Specimen on display at the Paleontological Museum in Santana do Cariri, few cm in size.
Cannibalism
Cannibalism exhibited by the fish Dastilbe crandalli, Cretaceous Crato Fm., Brazil. Specimen on display at the Paleontological Museum in Santana do Cariri. Larger fish is about 10 cm in size. Unique environmental conditions are required for such spectacular preservation of fossil fish. This form of cannibalism is also interpreted as indicative of stressful environmental conditions.
Fossilization styles
Two types of fossils preserved in close proximity. The herring-like fish, Dyplomystus dentatus, consists of actual bone remains. The gastropod is an internal mold made of sediment, with the original shell being dissolved. Slab is about 10 cm in size, on display at the Chicago Field Museum of Natural History. From Eocene deposits, Fossil Lake, Wyoming.
Tiktaalik roseae
A cast of a famous specimen (about 50 cm in size) of the lobe-finned fish Tiktaalik roseae, from the Devonian of Canada, on display at the Field Museum of Natural History, Chicago. Tiktaalik is often presented as a "missing link" in tetrapod evolution. However, as it often happens, the picture of "sequential transitions" is much more complicated when looked at in detail, with mosaic distribution of characters between various forms.
Mass mortality
5 different organisms (a soft-shelled turtle, 3 species of fish, and an insect) are preserved in close proximity on this slab from the Eocene Fossil Lake Basin, Wyoming (on display at the Field Museum of Natural History, Chicago).
Xiphactinus audax
Predation is documented in the fossil record by exceptional specimens like this large fish from the Upper Cretaceous Niobrara Formation (KS, USA). When it died, the remains of its last meal (another large fish) were still partly undigested in its stomach. The incredible preservation of this fully articulated specimen (fins included) points to rapid burial and special taphonomic conditions. Photo taken at the Denver Museum of Nature & Science (CO, USA).