Only one fossil of the single and type species, T. boylei, has been discovered in deposits of the Late Silurian period (Ludlow epoch) in Elora, Canada.

It is a poorly-known genus whose carapace (dorsal plate of the prosoma, head) was semiovate bordered by a marginal rim, with eyes laterally placed, a preabdomen and postabdomen (the two halves of the abdomen) with six segments each and a short spike-like telson (which was the posteriormost division of the body).

This thickness that its body possessed is due to the highly saline conditions to which Tylopterella had to adapt in the Guelph Formation; other organisms with reinforced shells have also been found in the same place.

Each of the second to fifth tergites (dorsal half of the segment) carried in its median line a pair of single large, solid, prominent and elongated tubercles or knobs.

[2] Tylopterella is known by one single specimen (making it the holotype, GSC 2910, housed at the Museum of the Geological Survey of Canada)[3] preserving the carapace, segments and telson.

[1] In 1912, the American paleontologists John Mason Clarke and Rudolf Ruedemann identified E. boylei as an aberrant form sufficiently different from Eurypterus to have its own subgenus, Tylopterus.

This was favored by features like the short and compact body in general or the thick calcareous-chitinous integument of E. boylei, unlike Eurypterus, in which it was only chitinous.

[6] In 1962, a species of Stylonurus, S. menneri, was assigned to Tylopterella by the Russian paleontologist Nestor Ivanovich Novojilov based on the possession of paired tubercles in the tergites, a characteristic dubiously present in only one specimen of S.

[3] However, this species was redescribed in a 2014 study led by the British paleontologist David J. Marshall, determining that it did not represent a eurypterid, but a new chasmataspidid genus which was named Dvulikiaspis, thus rendering Tylopterella monotypic again.

[3] Alkenopterus was assigned to Onychopterellidae three years later because of the detection of a movable spine in the swimming leg, rather than a simple projection (a protruding body part) as previously thought.

[11] It is thought that the extreme thickness of the body surface of Tylopterella is due to the hypersaline conditions (with salinity levels higher than those of the sea) to which the fauna of the Guelph Formation was exposed and to the life in coral reefs continually hit by waves.

The environment in which it lived is considered to be a shallow and subtidal (that is, the sunlight reaches the bottom of the ocean) sea, and its lithology (the physical characteristics of the rocks) consists mainly of dolomite with presence of petroleum.