Where to find modeling tutorials – insects/plants/fossils?

Hi, I am interested in modeling the natural world e.g. plants, flowers, insects, vertebrae/invertebrae, fossils, etc. I prefer to create a fairly realistic model as opposed to a cartoon. Does anyone know where I might find a tutorial on at least one of the above?

Thank you very much.

http://docs.mcneel.com/rhino/6/usersguide/en-us/html/ch-17_dragonfly.htm

Yep! That’s exactly the type of tutorial I was looking for. Thank you.