Scientific Illustration

lindsay-lombard:

fact and fiction show final pieces

biomedicalephemera:

Jaws of the Hare

You can see the teeth of the hare in the cutaway of the jaws. Note the “clipping”-oriented incisors, with the grinding-oriented molars. These are very similar to rodent teeth, having continually-growing incisors covered with enamel on the anterior surface, but with exposed dentine on the posterior surface. As dentine wears away much more easily than enamel, it serves as a “self-sharpening” system to keep the teeth in gnawing-condition.

Despite these similarities, the teeth of rodents and lagomorphs are the result of convergent evolution, rather than being closely related. The difference that first led scientists to believe this (before it was proved by analysis of the inner-ear bones and other anatomical features, and, much later, genetics) is that lagomorphia are far more herbivorous than rodentia, and as such, do not have pre-molars, or any evidence of having had them. Their palate anatomy and digestive tract differs significantly because of this.

The Handy Natural History. Ernest  Protheroe, 1910.

biomedicalephemera:

Relative size of whale to man.

This is a fin whale (or Rorqual). It’s the sixth-largest animal on earth, after the blue whale, right whales, and bowhead whale. Unlike those larger whales, the fin whale isn’t lumbering and girthy.

Rorquals were often called the “greyhound of the sea” by whale fishermen due to their slender build and speed when chased; nevertheless, the Antarctic fin whale had over 750,000 animals killed in the 19th and early 20th century, and only about 15,000 remain today. The North Atlantic fin whale is somewhat better off, but never had high populations of individuals to begin with. 

Even though fin whales don’t reproduce quickly, they’ve recovered significantly since hunting bans were enacted. For example, the population around Greenland increased by nearly 4,000 individuals between 1974 and 1989, even given Indigenous Subsistence Legislation allowing the Inuit of the country to hunt the whales for food and oil - the skiffs of the Inuit are ill-suited to chase down fast whales, and the total take for the year of 1989 was 4 individuals, 2 of which were already injured and debilitated from unknown causes.

The Principal Forms of the Skeleton and of the Teeth. Dr. Richard Owen, 1854.

biomedicalephemera:

Anatomy of the upper jaw and mandibular musculature.

Traite de la Cephalotomie, ou Description Anatomique. Compiled by chief surgeon at Avignon. Published by Francois Gerard, 1748.