Paleonelumbo cf. macroloba Knowlton, 1930

Wang, Hongshan & Dilcher, David L., 2018, Early Cretaceous angiosperm leaves from the Dakota Formation, Hoisington III locality, Kansas, USA, Palaeontologia Electronica (34 A) 21 (3), pp. 1-49 : 20

Paleonelumbo cf. macroloba Knowlton, 1930

Figure 12

Description. Leaf incomplete. Base peltate central; margin lobed with glandular teeth. Primary venation actinodromous with at least eight primary veins extending directly into individual lobes; sinus depth varying from one tenth to one half length of primary vein. Pinnate secondary veins present on the distal portion of lamina, brochidodromous. Tertiary and quaternary veins random reticulate. Vein of higher order not observed.

Number of specimens examined. 1.

Specimens illustrated. UF 15826-24649 ( Figure 12 ).

Occurrences. Hoisington III locality, Kansas.

Remarks. One incomplete specimen is observed. This specimen is different from other Cretaceous and Cenozoic species that are assigned to Nelumbonaceae (Saporta, 1894; Berry, 1911d; Knowlton, 1922, 1930; Brown, 1933, 1962; Matsuo, 1954, 1962; Upchurch et al., 1994; Johnson, 2002; Barclay et al., 2003; Gandolfo and Cúneo, 2005; Estrada-Ruiz et al., 2011) in that the specimen from Hoisington III locality is lobed with varying depth of sinus and toothed margin. This specimen resembles Paleonelumbo macroloba Knowlton (Knowlton, 1930, plate 39, figure. 3, plate 42, figures 3, 4; Brown, 1963, plate 35, figure 7; Johnson, 2002; Barclay et al., 2003, figure 9 A) and Nelumbo tenuifolia (Lesquereux) Knowlton (Knowlton, 1922, plate 26, figure 7) in having a lobed lamina. They differ in that (1) the Hoisington III specimen has fewer primary veins; (2) it has veins of primary to tertiary order entering the marginal teeth; and (3) it does not possess transverse tertiary veins.

This leaf appears to be sagittate in shape but it only has one pointed lobe. The direction of this lobe is unknown since the leaf is incomplete. The deep sinus ( Figure 12.1 ) does not seem to be the result of insect or mechanical damage since there are consistent looping veins along the margin. We tentatively assign this specimen to Paleonelumbo macroloba because its morphology is more similar to this species than other species assigned to Nelumbonaceae .

Figures

FIGURE 12. Paleonelumbo cf. macroloba Knowlton, 1930. 1, UF15826-24649, specimen showing primary venation (scale bar equals 5 mm) and 2, enlargement to show high order venation and toothed margin (scale bar equals 1 mm).