boa and python

Question
Hello

My question isn't about pet boas or pythons I'm more interested in wanting to know the anatomy for the two for a research paper.  I researched online about the differences between the two I get different answers from different websites or different people.  I know that boas give live birth to live young and pythons lay eggs.  I know that they have skeletal differences especially in the head.  But the thing that confuses me are the number of teeth and heat sensing pits.
 
I know pythons have more teeth than boas but do they have more rows of teeth or just more teeth in that one row?

Also don't boas have heat sensing pits as well or no?  This question is what confuses me the most as many people over the internet claims different and argues the fact that boas don't have heat pits and some people say that they do.  Is it because some boa species have heat pits while other boa species do not?  Or are people seeing something on the boas face and are getting confused?  I'm looking at pictures of boas and I don't see any but I came across a face shot of a emerald tree boa and it looks like it has very distinct heat sensing pits or is it something else?

http://familytrees1.com/emerald-tree-boa



Thank you for your time.

Answer
Hi Thomas,

I believe that the difference with the heat pits between pythons and boas is the location  on the labial scales. I have always understood that pythons' pits are in the middle of the scales while the pits on boas (the species that have actual pits) are located in between the labial scales. It is also my understanding that many boa species that lack pits still have the ability to detect prey through temperature.  

This is a tree boa, notice how the pits appear to line up with the lines between the scales.

http://animalfarmguyana.com/images/large/Emerald_tree_boa.jpg

These two photos are tree pythons, the pits are in the middle of the scales.

http://lewisryan.co.uk/images/animals/green_tree_python.jpg

http://pixdaus.com/single.php?id=160970

These sites discuss the differences in skull anatomy with the pythons possessing a pair of supraorbital bones (one above each eye) that all but one species of boa lack. Most pythons also have teeth on their premaxilla bone ( right at the front of the upper jaw, under the snout) that boas lack.
They also mention the few oviparous (egg laying) boas, a couple sand boas and the Calabar boa (previously classified as a python).

http://www.jiffynotes.com/a_study_guides/book_notes/grze_07/grze_07_00471.html

http://www.jiffynotes.com/a_study_guides/book_notes/grze_07/grze_07_00472.html

http://www.environment.gov.au/biodiversity/abrs/publications/fauna-of-australia/...