Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Q: Sentence1: Lions live in social groups called prides. 
Sentence2: Chimpanzees live in social groups called communities.

A: groups
****
Q: Sentence1: Scyphozoans are the next group of Cnidarians, and they are the familiar jellyfish. 
Sentence2: Scyphozoans are aquatic organisms.

A: Scyphozoans
****
Q: Sentence1: Cynodonts are the therapsids from which mammals evolved. 
Sentence2: some therapsids became more mammal-like as they continued to evolve.

A:
therapsids
****