[1][2][3] Hayward noted that the group was a side project for all the musicians involved, and commented: "We didn't have any commercial intentions for this band... We just wanted to get together and make some music we liked; it was just about playing.

"[4] In a review for AllMusic, Glenn Astarita wrote: "the quartet goes straight for the jugular via a no-nonsense approach; however, the artists pay strict attention to compositional form.

"[1] Todd S. Jenkins, writing for All About Jazz, called the album "an edgy, exciting session that stands with the best of Tone Center's releases so far," and stated: "Endangered Species is a fascinating listen from beginning to end, with all the suspense one expects from a good jam band but none of the ennui that comes from overbearing chops.

"[5] Michael Lello of Jambands.com commented: "if you want to hear one of rock's best yet mostly unheralded guitarists, a versatile keyboardist... and a tight, expressive rhythm section, this disc is for you.

"[6] Modern Drummer's Mike Haid remarked: "A perfect counterpoint to the heavy rock fusion chops of the rest of this band, Hayward plays with a loose, dirty style with little polish but lots of grit...