Predator and prey

Dan Quinsey (UK) Some fossils show evidence of the violent relationships between predator and prey. Below is a brief discussion of a few of such fossils – fossils that seem to preserve the moment when a carnivore has killed its victim or scavenged a dead body for food. Fig. 1. Placenticeras sp ammonite with limpet (insert) holes show a slightly dissolved and smooth edge to the shell around the holes. Predator: MosasaurPrey: Ammonite Modern mammals, fish, and reptiles feed on squid and octopus. Therefore, it can safely be assumed that ancient reptiles and fish fed on their ancient relatives – the ammonites. In fact, ammonites exhibiting bite marks are not uncommon. However, such bite marks are often mistaken by the collector as being just the result of random brakes in the shells. On the other hand, there have been claims of hundreds of ammonites with the preserved tooth marks of mosasaurs. Most of these claims are false. The marks on most of the shells are holes bored or dissolved in the ammonite by limpets or other forms of gastropods, rather then holes made from the bite of such reptiles. The Placenticeras specimen, on the right, is a fine example of a mosasaur-bitten ammonite. The tooth marks have been left in the phragmocone (chambered portion) of the shell. Here, the septa still supports the surrounding shell as the bite did not result in the wide scale collapse of the shell around the holes. The edges of the holes show an irregular, … Read More