Dakotanthus

Name

Dakotanthus

Rank

Genus

Authors (Pub.)

Manchester S. R. Dilcher D. L. Judd W. S. Corder B. Basinger J. F.  

Publication

Early Eudicot flower and fruit: Dakotanthus gen. nov. from the Cretaceous Dakota Formation of Kansas and Nebraska, USA [2018/6]

Journal

Acta Palaeobotanica

Volume

58

Issue

1

Page number

32

Year

2018

Parent Taxon

[Class] Magnoliopsida

Fossil Status

flowers

Type

Dakotanthus cordiformis

Diagnosis

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 f lower 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.