Dakotanthus cordiformis (Lesq.) Manchester, Dilcher, Judd, Corder et Basinger

Plant Fossil Names Registry Number: PFN000440

Act LSID: urn:lsid:plantfossilnames.org:act:440

Authors: S. R. Manchester, D. L. Dilcher, W. S. Judd, B. Corder & J. F. Basinger

Rank: species

Basionym: Carpites cordiformis Lesq.

Genus: Dakotanthus Manchester, Dilcher, Judd, Corder et Basinger

Reference: Manchester, S. R., Dilcher, D. L., Judd, W. S., Corder, B. & Basinger, J. F. (2018): Early Eudicot flower and fruit: Dakotanthus gen. nov. from the Cretaceous Dakota Formation of Kansas and Nebraska, USA. – Acta Palaeobotanica 58(1): 27–40.

Page of description: 29

Illustrations or figures: pl. 3, fig. 11

Types

Original diagnosis/description

Fruit deeply impressed into the stone, cordiform, separated in the middle by a deep, linear furrow, as though composed of two narrowly obovate ovules, which are straight and confluent in the middle, rounded above, curved on the sides, pointed at the upper end, convex on the surface.

Emended diagnosis

Manchester et al. (2018): Acta Palaeobot., 58(1): 32–33:
Flowers 22–30 mm diameter, 14–19 mm high, with two five-merous, hypogynous perianth whorls. Calyx thick, persistent; calyx lobes ovate, 10–13 mm long (from center of flower to apex of calyx lobe), 4.7–8.7 mm wide. Petals spathulate, membranous, 12–15 mm long, 10–15 mm wide, attached near base of gynoecium. Ovary dome-shaped, 8–10 mm wide, pentacarpellate with five locules. Five styles diverging from common point at apex of ovary, each with capitate stigma. Five crescent-shaped nectariferous pads situated at base of gynoecium and opposite and adnate to each sepal. Ten stamens inserted at level of the nectaries, one whorl organized opposite sepals (each at apex of a nectary lobe) and the other whorl opposite petals (and in sinus between adjacent nectary lobes). Stamens consisting of filament 5–7 mm long with flared base and dorsifixed ovate-ellipsoidal anther 3–6 mm long, 2.7–3.5 mm wide. In situ pollen oblate, triaperturate, grains oblate to spheroidal, 8–12 μm in equatorial diameter; apertures appear porate at surface but frequently somewhat torn meridionally, possibly along short colpi; ornamentation finely verrucate. Fruits globose to ovoid, five-valved loculicidal capsules, 10–12 mm wide and high, borne on thick, short pedicels (2 mm wide, 3 mm long) and with persistent sepals and persistent nectaries; capsules with thin septa, opening without central column.

Stratigraphy

Cretaceous, Lower Cretaceous, Albian
Dakota Formation (sandstone) [stratigraphy according to Manchester et al. (2018): Acta Palaeobot., 58(1): tab. 1]

Locality

United States
39°16.212′ N, 97°38.377′ W, Ottawa Co., Kansas [locality according to Manchester et al. (2018): Acta Palaeobot., 58(1): tab. 1]