[1] Cyphophthalmi are smaller than the more familiar "daddy long-legs" harvestmen, with adults ranging from 1 to 7 mm in length.

Their coloration is almost always some shade of brown, with a heavily sclerotized body, and they are quite inconspicuous, residing in leaf litter or in caves.

They further differ from most harvestmen in that the first 8 opisthosomal tergites and the prosomal carapace are fused together in what is known as a scutum completum, although this feature is also known from the unrelated family Sandokanidae.

Cyphophthalmi possess more elaborate musculature associated with the defensive glands than other harvestmen, and the secretions, which primarily consist of a variety of naphthoquinones and ketones, are thought to be more potent than in Eupnoi and Dyspnoi.

As they did not disperse onto any oceanic islands, and it is believed that they did not travel between separate landmasses, they make an interesting subject for biogeography.

Each of the six currently recognized families has a distinct distribution:[2] Colombia shows the largest diversity of cyphophthalmids among countries in South America.

This could reflect the large number of ecosystems found there, but could also be due to a high rate of sampling in this country.

[6] A fossil cyphophthalmid assigned to a modern genus, Siro platypedibus Dunlop & Giribet, 2003 (Sironidae), was described from Paleogene aged Bitterfeld amber of eastern Germany.

[7] As the fossil record for Cyphophthalmi is so sparse, recent studies have attempted to predict the diversification time of the suborder by using molecular clocks and comparing gene sequences among living taxa.

[2] These two infraorders were never recovered as monophyletic in subsequent studies, and, following a 2012 phylogenetic analysis, a new Cyphophthalmi taxonomy was proposed.

[12][13][14] The monophyly of most subgroups of Cyphophthalmi is well supported, although both Boreophthalmi and Sironidae have been recovered as paraphyletic in recent analyses.