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About this episode

This is a New Series I am working on that will introduce people to fossils in the fossil record. Here's the Script: Hi Everyone. This is King Mike, and Welcome to my new series called So You Think Missing Links Dont Exist. Thats the name of my show. In this series, we are going to explore transitional fossils in the fossil record that span millions and millions of years in the making. While were at it, were going to have some fun and anyone any age could watch this show to learn about many fossils. This first episode, we will look at some funny looking creatures classified as Nautiloids. For starters, they are large and diverse group of marine cephalopods. They belong to the subclass Nautiloidea that began in the late Cambrian Period. Today, they are represented by the living Nautilus. The Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, and developed an extraordinary diversity of shell shapes and forms. As of today, some 2,500 species of fossil nautiloids are known, but only a handful of species have survived. Nautiloids are often found as fossils in early Paleozoic rocks. The shells of fossil nautiloids may be either straight (such as orthoconic as in Orthoceras and Rayonnoceras), curved (for exampled Cytroceras), coiled (for example Cenoceras), or a helical coil (as in Loeierosceras). The shells are formed of aragonite, although the cameral deposits may consist of primary calcite. (1) The rocks of the Ordovician period in the Baltic coast and parts of the United States contain a variety of nautiloid fossils, and specimens such as Discitoceras and Rayonnoceras may be found in the limestones of the Carboniferous period in Ireland. The marine rocks of the Jurassic period in Britain often yield specimens of Cenoceras, and nautiloids such as Eutrephoceras are also found in the Pierre Shale formation of the Cretaceous period in the north-central United States. Nautiloids are first known from the late Cambrian Gengshan Formation of northeastern China, where they seem to have been quite diverse. However, although four orders have been proposed from the 131 species named, there is no certainty that all of these are valid, and indeed it is likely that these taxa are seriously oversplit References: http://www.jstor.org/stable/2400474 Stehli, F. G. (8 June 1956). "Shell Mineralogy in Paleozoic Invertebrates". Science 123 (3206). KrÖger, B. ?R.; Landing, E. (2008). "Onset of the Ordovician cephalopod radiation evidence from the Rochdale Formation (middle Early Ordovician, Stairsian) in eastern New York". Geological Magazine 145 Kröger, B.; Yun-bai, Y. B. (2009). "Pulsed cephalopod diversification during the Ordovician". Palaeogeography Palaeoclimatology Palaeoecology 273 Music: Introduction Justice- "D.A.N.C.E." Credits: Pearl Jam- "The Fixer"

• Release Date

  Jan 24, 2010

• Runtime

  03:27