snip "I haven't been proven wrong.

And chitinase isn't found in ANY animals. It is found in some bacteria and some plants!"endsnip

For one example in a vertebrate (a crab eating Bufo)
see http://cat.inist.fr/?aModele=afficheN&cpsidt=13789265 for the abstract of

OSHIMA Hiroyuki; MIYAZAKI Rieko; OHE Yoshihide; HAYASHI Hiroaki; KAWAMURA Kosuke; KIKUYAMA Sakae; Isolation and sequence of a novel amphibian pancreatic chitinase; 1994; Comparative biochemistry and physiology. Part B. Biochemistry & molecular biology (Comp. biochem. physiol., Part B, Biochem. mol. biol.)

As this is a pancreatic enzyme it rules out chitinase being the result of a symbiotic relationship.

For another see
Isolation and Characterization of a Chitinase from the Nine-Banded Armadillo, Dasypus novemcinctus
Stephanie A. Smith, Lynn W. Robbins, John G. Steiert
Journal of Mammalogy, Vol. 79, No. 2 (May, 1998), pp. 486-491
doi:10.2307/1382979

And many fungi contain chitinases and they are neither bacteria or plants.

Ed