Paraplacodus
Encyclopedia
Paraplacodus was a Placodont
from the middle Triassic
period, during the Anisian
to Ladinian
stages. The fossil
s were uncovered in Northern Italy
and the species was named in 1931 by Bernhard Peyer. Paraplacodus means "Almost Placodus", and thus far only one species, P. broilli, has been identified, although as the name suggests, it was similar to Placodus
, and also bore a strong resemblance to Saurosphargis.
Like all known Placodonts, Paraplacodus was an aquatic reptile
that fed almost exclusively on shellfish
. Most known Placodont species can be divided into two groups - the unarmored placodontoids, which would resemble a large, scaly, tooth-filled newt
, or the armored cyamodontids, which would resemble a heavily-armored turtle
; Paraplacodus would have been in the newt-like family, but grew to a length of 1.5 meters (4.5 feet).
The jaws of Paraplacodus were adapted to eat shellfish, with three pairs of protruding teeth in the top row and two rows of protruding teeth in the front of the jaw
, with rounded crushing teeth in the upper and lower jaws. Thick ribs formed a box
-like ribcage with an almost-square cross-section, which enabled Paraplacodus to remain close to the seabed
while hunting for food.
Placodont
Placodonts were a group of marine reptiles that lived during the Triassic period, becoming extinct at the end of the period. It is believed that they were part of Sauropterygia, the group that includes Plesiosaurs...
from the middle Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
period, during the Anisian
Anisian
In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 245 million years ago until 237 million years ago, approximately...
to Ladinian
Ladinian
The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 237 ± 2 Ma and 228 ± 2 Ma...
stages. The fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s were uncovered in Northern Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
and the species was named in 1931 by Bernhard Peyer. Paraplacodus means "Almost Placodus", and thus far only one species, P. broilli, has been identified, although as the name suggests, it was similar to Placodus
Placodus
Placodus was a genus of marine reptiles, belonging to the order Placodontia, which swam in the shallow seas of the middle Triassic period...
, and also bore a strong resemblance to Saurosphargis.
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
that fed almost exclusively on shellfish
Shellfish
Shellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some kinds are found only in freshwater...
. Most known Placodont species can be divided into two groups - the unarmored placodontoids, which would resemble a large, scaly, tooth-filled newt
Newt
A newt is an aquatic amphibian of the family Salamandridae, although not all aquatic salamanders are considered newts. Newts are classified in the subfamily Pleurodelinae of the family Salamandridae, and are found in North America, Europe and Asia...
, or the armored cyamodontids, which would resemble a heavily-armored turtle
Turtle
Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...
; Paraplacodus would have been in the newt-like family, but grew to a length of 1.5 meters (4.5 feet).
The jaws of Paraplacodus were adapted to eat shellfish, with three pairs of protruding teeth in the top row and two rows of protruding teeth in the front of the jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
, with rounded crushing teeth in the upper and lower jaws. Thick ribs formed a box
Box
Box describes a variety of containers and receptacles for permanent use as storage, or for temporary use often for transporting contents. The word derives from the Greek πύξος , "box, boxwood"....
-like ribcage with an almost-square cross-section, which enabled Paraplacodus to remain close to the seabed
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
while hunting for food.