The Nayabaru are a species descended from Earth's iguanodonts. As a culture, they fear death, criminalising suicide, and are more accepting of someone torturing another than they would be of a mercy killing. (Though, don't misunderstand, torture is still not cool, it's just much better than murder.)
Nayabaru are covered by very small scales, giving them a fairly smooth skin. The colouration of the skin ranges from ochre to a reddish-brown. Their irides are predominantly blue (~55%) and green (~40%), with the occasional light amber.
Nayabaru mutual strangers usually greet each other properly after the initial address with a customary handshake: With the thumbspike pointed toward one's own chest, their opposable digit is offered to the other party for interlocking with their own. There are two social variants of the handshake expanding to three variants for individual Nayabaru:
The first is the neutral one, where a Nayabaru's palm points to either their left or right side. The chiral designation of the hands is unimportant - Nayabaru are ambidextrous and assign no connotation to their right hand that their left does not also have, and vice versa. The orientation of fingers is also unimportant - they can point in the same or opposite direction of their greeting partner's, depending on which position is more comfortable. The standard hand-shake is of hands of matching handedness (i.e. right to right, or left to left), with the remaining non-spike fingers pointing upward, but other constellations are entirely conceivable (see image).
The second is the socially hierarchic one, where the superior Nayabaru's palm points down and the inferior Nayabaru's palm points up. It's customary for the inferior Nayabaru to initiate such a handshake - the superior one doing so would, depending on the degree of social separation, prompt anything from unease to unadulterated terror in the inferior Nayabaru, since it implies that their subservience is unquestioningly expected of them (which in turn implies there is something their unflinching subservience is needed for).
As one might expect from a sapient species, Nayabaru are quite creative with their courtship, their efforts ranging from feats of physical strength to poetry much as in human beings.
Nonetheless, an instinctive attachment to their thumbspike's importance in keeping family safe means that physical efforts involving the spike are considered the most noble and impressive. Perhaps ironically (given the roots of the thumbspike as a means to ward of predators), the most commonplace way of showing off ones prowess as a mate is to climb trees, using the thumbspikes to anchor oneself in the wood.
Nayabaru have a pronounced fight-or-flight instinct that appears complex on the surface but can be reduced to a few axioms:
Juvenile Nayabaru are not protected significantly more than adult Nayabaru, and the species does not put a greater value on either sex, meaning that social stress situations tend to reduce down to a simple numbers game… unless other factors make certain emphases apparent, such as an attack specifically on juvenile Nayabaru prompting protection especially of, well, juvenile Nayabaru.