Rhizodontidae - Anatomy

Anatomy

The upper jaw had a marginal row of small teeth on the maxilla and premaxilla, medium sized fangs on the ectopterygoid and dermopalatine bones, and large tusks on the vomers and premaxillae. On the lower jaw there were marginal teeth on the dentary, with fangs on the three coronoids and a huge tusk at the symphysial tip of the dentary. Apparently, the left and right mandibles have rotated inwards towards each other on biting. This may have been a kinetic mechanism to dig the marginal teeth more deeply into the prey, to help grip slippery or struggling items.

Rhizodonts' trunk was elongated, with pelvic, two dorsal and anal fins much reduced and placed posteriorly The anal and second dorsal fins formed a functional part of the tail. The lateral line system was elaborated on the skull and pectoral girdle - in Strepsodus the main trunk lateral line also had several subsidiary lines running parallel to it. This probably helped rhizodonts detect prey in the turbid, swampy environment where they lived.

Rhizodont pelvic fins are known only from external morphology. They are smaller than the pectoral fins and positioned toward the rear of the body. In comparison to the other fins, the pectoral fins were much enlarged. They had a well-developed internal skeleton surrounded by robust, largely unsegmented lepidotrichia; the whole fin was then covered in deeply overlapping scales. This turned the pectoral fin into a broad paddle.

Read more about this topic:  Rhizodontidae

Other articles related to "anatomy":

Somatosensory System - Anatomy - Brain
... A relationship between the somatosensory cortical areas and their projection of the body was discovered by recording electrical activity in the human cortex after mechanosensory stimulation of different body parts during neurosurgical procedures ... These data led to the construction of somatotopic maps in which a Somatotopic arrangement was generated ...
Pale-throated Sloth - Description - Anatomy
... The mouth is lined by a black colored mucosa, although the large and heavy tongue is pink ... The palate is wrinkled in texture, and the tongue is lined with numerous grooves, apparently adaptations to the sloth's diet ...
Guy De Chauliac - Works - Chirurgia Magna - Emphasis On Anatomy
... belief that surgeons should have a thorough understanding of anatomy ... wrote, "A surgeon who does not know his anatomy is like a blind man carving a log" ...
Anatomy - Other Branches
... Comparative anatomy relates to the comparison of anatomical structures (both gross and microscopic) in different animals ... Anthropological anatomy or physical anthropology relates to the comparison of the anatomy of different races of humans ... Artistic anatomy relates to anatomic studies for artistic reasons ...
Prosector
... prosectors working for lecturers and demonstrators in anatomy and pathology ... by a prosector – a person who is well versed in anatomy and who therefore prepares a specimen so that others may study and learn anatomy from it ...

Famous quotes containing the word anatomy:

    But a man must keep an eye on his servants, if he would not have them rule him. Man is a shrewd inventor, and is ever taking the hint of a new machine from his own structure, adapting some secret of his own anatomy in iron, wood, and leather, to some required function in the work of the world. But it is found that the machine unmans the user. What he gains in making cloth, he loses in general power.
    Ralph Waldo Emerson (1803–1882)

    I love to see, when leaves depart,
    The clear anatomy arrive,
    Roy Campbell (1902–1957)

    Man is a shrewd inventor, and is ever taking the hint of a new machine from his own structure, adapting some secret of his own anatomy in iron, wood, and leather, to some required function in the work of the world.
    Ralph Waldo Emerson (1803–1882)