Is it a Bird? Is it a Dinosaur?

I had planned to teach, yet again, about muscles and bones.  Just the other week we dissected chicken legs to separate out the muscles that are attached to the tendons that operate the individual toes, and had gruesome fun making the toes wiggle in turn.  

Sometimes teaching is led by the students.  Today the student noticed the resemblance of the bird legs and toes to images he has seen of dinosaurs.  Thus ensued a brilliant discussion on the evolutionary relationship between reptiles and birds. 

Archaeopteryx was a fossil found in Germany in the 1860 s that has since been called 'the transition fossil'.  It is thought to represent a species from about 150 million years ago which is half dinosaur and half bird, indicating that the one evolved into the other.

From Muscles to Mussels - Dissection Club

You wouldn't have thought there was much to a bivalve, but when we opened up the shell, we found the soft tissue of the mantle also opened up to reveal the tiny structures inside. We could identify the muscular foot, the gills and the siphons.

Puff ball puffing

I came across this common puffball,  

Lycoperdon perlatum, at Calke Abbey today

Immediately obvious is the apical pore, and I could not resist stamping on it.  Prior to this I took a deep breath and shouted 'Run!' To the bemusement of the family.  Lo and behold a thick black puff of spores was exuded.  You really would not want to breathe them in; lycoperdonosis is an unpleasant lung disease.

Dissection Club - Octopi

The mantle is like a pouch that is open on the underside.  Water is taken in and squirted out to provide propulsion.

Just where the tentacles are attached is the mouth which contains the beak.  The beak is the only tough material in this soft bodied animal.  It is used to lever open bivalves.

Underneath the mantle can be found the heart, reproductive organs and in this case, egg, as seen here.