Main head morphological differences between the two species.

<p>Morphological characterisation of the head of <i>Iguana iguana</i> (Fort Saint-Louis, Martinique). 1. Subtympanic plate. 2. Lower sublabial scales forming a mosaic. 3. Flat sub-labial and labials. 3’. No row of oval scales between the labials and sub-labials. 4. Dewlap edges forming nearly a right angle. 5. Gular spikes extending into the lower half of the dewlap. 6. Gular spikes > 10. 7. Triangular gular spikes. 8. Top of head flat. 9. Eye chestnut brown. 10. Nuchal tubercles. 11. Body colour greenish grey. 12. High dorsal crest scales. Morphological characterization of the head <i>Iguana delicatissima</i> (St. Barth). 1.No subtympanic plate. 2. Sublabial row of scales ± parallel to the labial scales. 3. Rounded scales. 3’. Row of oval scales between the labials and sub-labials. 4. Rounded dewlap edge. 5. Gular spikes on the straight upper edge of the dewlap. 6. Gular spikes <7–8. 7. Conical, long and more or less curved gular spikes. 8. Top of head bumpy. 8’. Occipital bumps. 9. Grey eye. 10. Lack of nuchal tubercles. 11. Body colour brownish-grey. 12. Moderately high dorsal crest scales.