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Integumentary Sense Organ (ISO)

Definition

Pressure and chemical sensory pits visible as small circular depressions on reptile scales. In crocodilians their distribution pattern distinguishes crocodiles from alligators and caimans in finished leather.

Location
Reptile scales, seen as small circular depressions
Function
Pressure and chemical sensing
Forensic use
Distinguishes crocodiles from alligators and caimans
Evidence type
Finished leather goods

Common questions

Why would ISO distribution survive in a finished leather product?+

Tanning and dyeing alter colour and flexibility but do not remove the scale surface topography, so the pit pattern that marks ISO placement remains visible on the grain surface of the finished hide.

What makes ISO pattern more reliable than scale shape alone for species identification?+

Scale shape can be distorted by stretching or cutting during manufacture, but the number and arrangement of integumentary sense organs per scale is a more consistent taxonomic character across crocodilian genera.

Related terms

CITES Leather Guide
A reference document maintained by the CITES Secretariat providing scale/pit patterns, macroscopic key characters, and species notes for major commercially traded reptile...
Histological Cross-Section
A 5-10 micrometre thin section cut perpendicular to the skin surface, stained and mounted for light microscopy. Reveals dermis architecture (collagen orientation,...
Lamellar Microstructure
The layer-cake cross-section of pangolin scales visible under light microscopy, reflecting the keratinised plates that build up the scale. Distinguishes pangolin scales...
Osteoderm
Bone embedded within the skin dermis, characteristic of crocodilians and some lizards. Survives tanning and provides a species-group identification marker visible as...
Pit Pattern
The arrangement of scale pits or ISO pores on reptile skin. Scale pit pattern is one of the primary characters in the...

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