![]() These genera have a significantly greater geographical spread when compared to non-surviving Ammonite genera. This idea is reinforced when the geographical spread of those genera that may have briefly survived into the Palaeocene is examined. This may have made the Ammonites more susceptible to an extinction event. The scientists discovered that most of the Ammonite genera at the very end of the Maastrichtian were restricted in their geographic distribution. The research team plotted the fossil data against two criteria, firstly they looked at all the occurrences of each genus and secondly they looked at the maximum distance between occurrences for each genus, an examination of geographical distribution based on an assessment of world geography at the end of the Mesozoic. To read more about Stevns Klint being granted UNESCO World Heritage status: Famous KT Boundary Gets UNESCO World Heritage Status The white arrows in pictures A and C indicate voids left after the dissolution of the original aragonite shell. Pictures A, B and D-H are fossils of the Ammonite Baculites vertebralis whereas picture C represents the species Hoploscaphites constrictus. The picture above shows Ammonite fossilised remains found in the Palaeocene aged strata at Stevns Klint and surrounding area. Landman has been at the forefront of these studies and he believes as many as six species may have lingered, sort of “dead clades swimming”.įragmentary Fossils of Ammonites from Stevns Klintįragmentary fossils indicate survival of some species into the Palaeocene Epoch. Fragmentary fossils representing two different genera of Ammonite have been identified from the strata immediately above the thin, dark line that marks the end of the Cretaceous. One such location is the cliffs at Stevns Klint on the Danish island of Sjaelland. ![]() In a few, very special locations the sequence of strata that was led down at the end of the Cretaceous (Maastrichtian faunal stage) and the first deposits of the Palaeogene (Palaeocene epoch, Danian faunal stage) can be identified. Perhaps the very last of this great group of marine invertebrates lived for a hundred thousand years or so before they too finally became extinct. What? Evidence of Ammonites surviving beyond the Cretaceous extinction event we hear you ask! There is some evidence to suggest that a few types of Ammonite did indeed survive into the Age of Mammals. ![]() ![]() The scientists also included information from a recently published study that looked at Ammonite genera that appear to have briefly survived beyond the Cretaceous into the Palaeogene. They then compared this data with the occurrences of the Nautiloid genus Eutrephoceras over the same period. Landman, mapped all the locations of Ammonite fossil finds in the last half a million years or so of the Cretaceous (Maastrichtian faunal stage). In this new study, the researchers including scientists from the Royal Belgian Institute of Natural Sciences, Saint Petersburg State University, Polska Akademia Nauk (Warsaw), Bowling Green State University (Ohio) and the Natural History Museum of Maastricht (Holland) as well as Dr. They are believed to be scavengers feeding on a variety of dead animal matter. These animals tend to be found in deep water (up to seven hundred metres, although more usually around three to four hundred metres) and they inhabit the deeper slopes of coral reefs in the Indo-Pacific. There are two extant genera of Nautilus alive today. The first Nautiloids can be traced back to the Late Cambrian, whilst the Ammonites are believed to have originated in the Devonian geological period. Although more closely related to today’s cuttlefish, Ammonites and their living relative the Nautilus both had coiled, chambered shells. Picture Credit: Everything Dinosaur/Safari LtdĪmmonites belong to the Class Cephalopoda and they seem to have been entirely marine, pelagic animals (living above the sea floor). Similar creatures but only the Nautilus is around today.
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