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BELEMNITE IN MATRIX - Drugendorf, Germany UPPER JURASSIC PERIOD (MALM): 154 - 144 million years ago While much more common to find loose without their host matrix or sliced in matrix tiles, this is a complete three-dimensional and solidly mineralized belemnite of the species Hibolites hastatus still attached to its original host rock as found. Rare for this type specimen is that the belemnite has not been broken from the excavation efforts and is completely intact. Also, ventral furrow is perfect and plainly visible. This Hibolites has been completely replaced with calcite and glows a translucent amber brown when held to the light. A fragment from another larger example is also present and the crystalline growth lines and inner structure can be plainly seen making this a unique double display specimen - a perfect and complete animal with the other offering a glimpse of what they look like inside. Excellent and recommended species in a much finer state of preservation than usually encountered.
Cephalopods evolved during the Late Cambrian Period. Their bodies were predominantly elongate with conical shells. Some of these creatures evolved into semi-coiled forms eventually giving rise to coiled cephalopods like ammonites and nautili. Another branch of straight-shelled cephalopods continued to coexist with the coiled forms on into the Pennsylvanian Period. These straight forms were much less diverse and abundant than the coiled cephalopods, as a whole. Straight cephalopods were among the most advanced invertebrates of their time having eyes, jaws, and a sophisticated nervous system. These creatures were predators that swam freely using a jet propulsion system by squirting water from their bodies. They had tentacles and ink sacs also much like the present-day squid. Except for belemnites, cephalopods had external shells with hollow internal chambers separated by walls called septa. A tube called the siphuncle, connected the body with the chambers allowing the animal to fill them with water or air, changing its buoyancy in order to rise or drop in the ocean. Only the last and largest chamber was occupied by the living animal. Belemnites were different than other straight cephalopods like Orthoceras in that they had internal shells called 'guards' which were covered with the soft, muscular tissues of their bodies. These shells were also chambered but much less complex than the straight varieties of nautiloids and ammonoids. The gas chamber by which the animal regulated its buoyancy is called the phragmocone. In finely preserved specimens, it is a conical, thin-walled opening at the posterior of the shell. Rare belemnite fossils complete with soft body parts have been found and provide us with a valuable glimpse of what these creatures looked like when alive. Belemnites possessed 10 tentacles and males had chitonous hooks which they used to grasp the females during mating. Straight cephalopods probably lived for one to six years, with the majority living two to four years. They fed on plankton (tiny free-floating organisms), sea lilies, and smaller orthoceras. Although many fed off the ocean floor, others may have caught plankton while floating or swimming via jet propulsion, expelling water through a funnel-like opening to propel themselves in the opposite direction. If you appreciate fossil specimens that are rarely seen on the market, then this example should appeal to you. The site where this fossil was collected is unique with no commercial production. A finely preserved and excellent display specimen of these once-prolific creatures of the ancient seas. TOP GRADE EXAMPLE OF THIS SPECIES AND IN RARE FORM UNBROKEN AND STILL IN MATRIX! 4.4" x 3.75 overall with matrix, belemnite is 1.9" long $95 BE-001 INCLUDES STAND Actual Item - One Only |
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BELEMNITES |
Belemnites
are extinct straight-shell members of the Cephalopoda that died out at
the end of the Cretaceous along with ammonites and dinosaurs.