[6][7] It is extremely similar to the Jamaican boa (Chilabothrus subflavus) which was seen as conspecific for some fifty years until they were split in 1901 by Leonhard Hess Stejneger.

[8] The taxon Piesigaster boettgeri was described from Mindanao in the Philippines, by the Spaniard es:Víctor López Seoane in 1881, but was identified as a synonym of this species by Stejneger.

[8] Although it has been known under the name E. inornatus for over a century, having been moved to the genus Epicrates (which had been created in 1830 by Johann Georg Wagler) by the Belgian zoologist George Albert Boulenger in 1893 when cataloguing the specimens in the Natural History Museum, London, a number of authors decided to it move to Chilabothrus inornatus in 2013.

It had first been moved to Chilabothrus inornatus from the genus Boa in 1844 by either the French herpetologists André Marie Constant Duméril and Gabriel Bibron,[4] or the Italian snake expert Giorgio Jan,[8] only a year after it had been described in that genus by the Dane Johannes Theodor Reinhardt in 1843.

The first was patterned with seventy to eighty indistinct dusky cross bars consisting of a row of spots, these cross bars increasing in width to the end of the snake; in the second these patterns were much more distinct, with the crossbars having pale centres but being outlined in blackish colour, the lateral spots being so aligned as to form a blackish line in the front third of its body, but in the last snake there was little evidence of patterning with only a few scattered and obscure darkish spots on its sides.

The dissections of 72 snakes from the West Indies show that while young boas of the genus Epicrates feed primarily on anoles, mature boas (with the exception of Epicrates gracilis) feed for some 60% on mammals combined, which distinguishes them ecologically from the other three genera of snakes on the island.

Impacts to the boa resulting from the oil trade were undoubtedly heightened by a concurrent reduction of habitat.

Deforestation of the island began during this period and continued until, by the early 20th century, very little natural forest remained.

Predation by the mongoose, introduced into Puerto Rico in the 19th century, has been postulated as a further cause for the boa's present status, but there is no direct evidence to support this idea.

In 1904 Stejneger mentions that during his time the snake was rather rare, he himself, as well as a number of other collecting parties in the newly acquired territory, were unable to see one during their expeditions on the island, although a trail of one was seen.