Species

Discoceras antiquissimum (Eichwald, 1842)

Taxon description

Kröger & Aubrechtová, 2019

Diagnosis (after Furnish & Glenister 1964). Gradually expanding conchs with a ribbed or smooth shell surface, characterized by a slight to moderate whorl overlap, circular to subquadrate whorl cross section, central position of siphuncle in initial half-volution, marginodorsal in succeeding 1.5–2 whorls, subdorsal at maturity, and thick, layered connecting rings.

Synonymy list

1840 Clymenia antiquissima Eichwald 1840 (nomen nudum) — Eichwald , pp. 115

1842 Clymenia antiquissima — Eichwald , pp. 33, fig. 3:16, 17

1843 Clymenia antiquissima — Eichwald , fig. 3:16-17

1860 Clymenia antiquissima m. — Eichwald , pp. 1301

1861 Lituites (Trocholites) antiquissimus — Schmidt , pp. 62, fig. 6:2a-g

1861 Lituites antiquissimus — Roemer , pp. 62, fig. 6:f-g

1869 Lituites antiquissimus — Karsten , pp. 52, fig. 19:7a-c

1885 Lituites antiquissimus — Karsten , pp. 68, fig. 4:12

1925 Discoceras antiquissimum — Foerste , pp. 17,58, fig. 18:1

1930 Discoceras antiquissimum (Eichwald, 1840) — Teichert , pp. 285

Selection of related publications

Kröger, B. 2025. The Lyckholm acme of cephalopods – Review of the late Katian (Vormsi–Pirgu regional stages) Ordovician cephalopods of Estonia. European Journal of Taxonomy 978, 1-168. DOI:10.5852/ejt.2025.978.2801

Kröger, B., Aubrechtová, M. 2018. Cephalopods from reef limestone of the Vasalemma Formation, northern Estonia (latest Sandbian, Upper Ordovician) and the establishment of a local warm-water fauna. Journal of Systematic Palaeontology 16, 10, 799-839. DOI:10.1080/14772019.2017.1347212

Stumbur, H. 1955. Eesti NSV ülem-ordoviitsiumi nautiloiididest [Diplomitöö. Juhendaja: A. Rõõmusoks]. pp. 1-159.

Balashov, Z. G. 1953. Svernutye i polusvernutye nautiloidei ordovika Pribaltiki. Trudy Vsesoûznogo Naučno-Issledovatel'skogo Geologo-Razvedočnogo Instituta (VNIGRI) 217-300. Gostoptehizdat.

Teichert, C. 1930. Die Cephalopoden-Fauna der Lyckholm-Stufe des Ostbaltikums. Paläontologische Zeitschrift 12, 3/4, 264-312. DOI:10.1007/BF03044452

Eichwald, E. 1860. Lethaea Rossica ou Paléontologie de la Russie. Premier volume. Ancienne Période en deux sections. pp. XIX+1–1657. E. Schweizerbart. DOI:10.5962/bhl.title.52391

Classification

Organism group	Biota
Kingdom	Animalia
Phylum	Mollusca
Class	Cephalopoda
Subclass	Tarphyceratia
Order	Tarphyceratida
Family	Discoceratidae
Genus	Discoceras
Species	amtjaernense
	angulatum
	antiquissimum
	arctuatum
	bandonis
	boreale
	costatum
	depressum
	fleischeri
	gubkovense
	ievense
	nilssoni
	paopense
	rarospira
	roemeri
	saemanni
	siljanense
	spongistriatum
	vasalemmense