The linked diagrams are interesting but a little overwhelming:<p>- <a href="https:&#x2F;&#x2F;www.math.ucdavis.edu&#x2F;~greg&#x2F;zoology&#x2F;diagram.xml" rel="nofollow">https:&#x2F;&#x2F;www.math.ucdavis.edu&#x2F;~greg&#x2F;zoology&#x2F;diagram.xml</a><p>- <a href="https:&#x2F;&#x2F;www.math.ucdavis.edu&#x2F;~greg&#x2F;zoology&#x2F;diagram.pdf" rel="nofollow">https:&#x2F;&#x2F;www.math.ucdavis.edu&#x2F;~greg&#x2F;zoology&#x2F;diagram.pdf</a>