Genus: Alcovasaurus GALTON, & CARPENTER, 2016
Etymology: In reference to Alcova, Natrona County, Wyoming, where the specimen was found, and Greek, sauros, "lizard."
= Natronasaurus ULANSKY, 2014a (nomen nudum)
Etymology: In reference to Natrona County, Wyoming, where it was found and Greek, sauros, "lizard."

Species: longispinus (GILMORE, 1914) GALTON, & CARPENTER, 2016
Etymology: Latin, longus, "long," and Latin, spina, "spine."
= Stegosaurus longispinus GILMORE, 1914
= Natronasaurus longispinus (GILMORE, 1914) ULANSKY, 2014a (nomen nudum)
= Miragaia longispinus (GILMORE, 1914) COSTA & MATEUS, 2019

Holotype: UW 20503 (formerly D54)

Locality: About 1 1/2 miles (-2.4 km) east of Alcova near Alcova Reservoir, Natrona County, Wyoming.

Horizon: Equivalent to the Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone?

Age: Kimmeridgian-Tithonian Stage, Malm Epoch, Late Jurassic.

Material: 42 vertebrae, fragmentary sacrum, 2 ischia, portion of one pubis, right femur, several ribs and 4 dermal tail spines.
Note: Lost?
Note: USNM has casts of the tail spines.

Tail spikes after Gilmore, 1914.

Referred material:

Locality: Griffin Ranch, ner Bone Cabin Quarry, Como Bluff, Albany County, Wyoming.

Horizon: Member? Morrison Formation.

Biostratigraphy: Zone?

Age: Age? Stage? Epoch? Late Jurassic.

Material:

MOAL (COSTA 2026): Fragmentary spike (cast DMNH 33431 GALTON & CARPENTER, 2016: Base of the huge spike).

= Miragaia longicollum COSTA, 2026

Locality: Cleveland-Lloyd Dinosaur Quarry, approximately 20 miles south of Price, SE 1/4, SE 1/4, Sec. 21, T17S, R11E, SLBM. lat 39°19’00", Long. 110°41’15"W, San Rafael Swell Area, Carbon County, Utah.

Horizon: Brushy Basin Member, Morrison Formation.

Biostratigraphy: Zone 3.

Age: Upper Part, Comobluffian age, Kimmeridgian Stage, uppermost Malm Epoch, Late Jurassic.

Material:

UMNH VP 5732: Fragmentary caudal spike.

UMNH VP 5572: Isolated cervical plate.

YPM PUI 14556: Medium size caudal spike, dorsal vertebra and 2 chevrons.