Xindi-Reptillian
The Xindi-Reptillian are a distinct and reptile-like species within the Xindi race.
In terms of musculature they were considierably stronger and had greater stamina than humans. Their neurological pathways were identifical to other Xindi despite their different appearance and anatomy.
History
Prior to contact with Humans, the Xindi devolved into a massive civil war between the six Xindi species. The Xindi-Reptillians aligned with the Xindi-Insectoids and in the 20th century (Earth Reckoning) the Insectoids and Reptilians detonated a seismic device that resulted in the extermination of the Xindi-Avians. After fleeing the destruction of their homeworld the surviving Xindi species migrated to the Delphic Expanse where they encounted "The Guardians", transdimensional beings that oversaw this region of space. In 2140 the Guardians appeared to the Xindi council and told the council that sometime in the future humanity would result in the destruction of the Xindi so the Xindi developed interstellar weapons and in 2153 launched their first attack against Earth. Earth responded by sending Cpt. Archer and the Enterprise to the Delphic Expanse to uncover the truth and make peace with the Xindi. While other Xindi races were swayed by Cpt. Archer, the Xindi-Reptilians and Xindi-Insectoids rejected the offer of peace and continued to attempt to attack Earth. In the end, the truth was revealed that the Guardians were using the Xindi as pawns and not protecting them was revealed. The Xindi-Reptillians were the last of the Xindi to be convinced but eventually were forced to admit that the humans were not the threat they had been told.Biology
Xindi-Reptillians are covered in a thick scaly skin that is highly resistant to damage. When humans first encountered them in in the 22nd century the phase-pistols and particle weapons used were ineffective. Xindi-Reptillians are carnivorous and prefer living food, primarily small rodent-like creatures. Their circulatory system was cold blooded causing them to be highly sensitive to temperature changes.In terms of musculature they were considierably stronger and had greater stamina than humans. Their neurological pathways were identifical to other Xindi despite their different appearance and anatomy.