Mostly only their head shields have been found; only one osteostracan has the head shield and squamation intact.
elegans shoal has preserved in a lens-like fish bed with rare ostracods and a few osteostracans (Tremataspis and Dartmuthia) occurring on the same bedding plane, while most of osteostracan and anaspid exoskeletons were buried under more agitated water conditions.
Kiaer in Oslo, while he himself published only a short popular-scientific paper on the osteostracans of Saaremaa (Luha 1940).
elegans as well as osteostracans were exported to several museums in Europe and North America.
martinssoni occurs together with the thelodont Thelodus laevis (Pander), the osteostracans
Tremataspis schmidti Rohon, Tremataspis milleri Patten, Saaremaaspis mickwitzi (Rohon), Oeselaspis pustulata Patten, Witaaspis schrenkii (Pander), Thyestes verrucosus Eichwald, and the anaspids Rhyncholepis parvula Kiaer, R.
Luha produced only a short paper on osteostracans
of Saaremaa (Luha 1940), but more than 70 examples were studied in Oslo and named Coelolepis luhai Kiaer, 1932, in a paper that was edited by A.
Its rare scales occur together with scales of thelodonts Thelodus marginatus Karatajfite-Talimaa, Paralogania martinssoni (Gross), Phlebolepis elegans Pander, osteostracans Tremataspis sp.
They come from grey and greenish-grey limestones with thin interlayers of clay containing also ostracodes, bivalves, and scales of thelodonts, fragments of osteostracans and anaspids.
Other vertebrates in the samples comprise Thelodus parvidens Agassiz, Thelodus sculptilis Gross, two to three different cyathaspidid heterostracans, two anaspids, two osteostracans, and acanthodians Nostolepis striata Pander, Gomphonchus sandelensis (Pander), and Poracanthodes porosus Brotzen.
The rock with the Thelodus specimen discussed in this paper is somewhat different from that in which Phlebolepis or osteostracans
were found: it is comparatively darker grey, argillaceous fine-grained, secondarily dolomitized dolostone, with indistinct horizontal microlamination.
and Paralogania martinssoni (Gross), as well as the osteostracans
Tremataspis schmidti Rohon and Tremataspis milleri Patten.
is similar to osteostracans
by having bone cell cavities in its exoskeleton.