part of part of has part has part in taxon Aves stomach digestive tract gizzard ventriculus BTO:0000520 gastric mill Wikipedia:Gizzard gigerium currently restricted to Aves, but may be found outside - e.g. Pangolins MESH:D005895 UMLS:C1510668 UBERON:0005052 GAID:1238 The muscular enlargement of the alimentary canal that has usually thick muscular walls and a tough horny lining for grinding the food and when the crop is present follows it and the proventriculus. BTO also includes: A thickened part of the alimentary canal in some animals (as an insect or an earthworm) that is similar in function to the crop of a bird. However, we are refering to the Aves structure here. NCIT:C77615 pyloric gastric gland