You will find that nearly all specimens from Messel, Germany will be encased in epoxy, resin, or Lucite. This is due to the fact that the shale layers that the fossils are found in are made up of about 40% water and 8% oil. When the water evaporates, the shale and the fossils become very unstable and they turn to powder. They are stabilized with epoxy, to prevent this decomposition, and later as time permits, they are encased in resin or Lucite. Atractosteus strausi was an alligator gar. Atractosteus comes from the Greek word atractos (meaning arrow). Gars are members of Lepisosteiformes and are found from the Permian Period to the present day. Their primitive traits are a heterocercal tail (meaning the upper lobe of the tail fin is larger than the lower with the end of the vertebral column prolonged and somewhat upturned in the upper lobe), a swimming bladder which is open to the pharynx that can function as a lung, and very hard armour-like ganoid scales. Because of their vascularized swim bladders most gars surface periodically to gulp air allowing them to live in stagnate waters which would kill most other fish. Gars are slow moving except when they strike at prey. They typically feed on smaller fish and invertebrates, such as crustaceans. Dimensions: 11-1/2" x 5-1/4" x 1"