![Thumbnail: [Volume 83, 1955-56 page 685]](/journals/rsnz/images/rsnz_83/thumbnails/rsnz_83_04_0819_0685_ac_02.gif)
Genus Ptilophyllum Morris
Ptilophyllum seymouricum n. sp. Text-Fig. 3, Figs. 8, 9.
Description. Portions of frond bearing alternately spaced pinnae, interspaces equal to the width of a pinna. Pinnae attached at a wide angle to the upper surface of a rachis by its entire base. Base parallel sided or slightly auriculate on upper edge, decurrent on lower. Pinnae tapering to point and bearing four to six parallel or slightly diverging veins, apparently all originating at rachis.
| Length | Length of pinnae | Width at base |
|---|---|---|
| Veins per pinna | ||
| (cm) | (cm) | (cm) |
| 356/12 | 3.3 | 1 -1.2 |
| 0.2 | 4 | |
| 356/14 | 2.1 | 1.2 |
| 0.15 -0.2 | 4-5 | |
| 356/4 | 6.2 | 0.7-1.2 |
| 0.175-0.25 | ||
| 356/30 | — | 1.3-1.6 |
| 0.2 -0.25 | 4-6 |
Loaclity. Seymour River, B356/30 (holotype) and B356/4 (figured paratype).
Age ? Turonian.
This species is similar in some respects to P. pecten (Phillips), a European Jurassic species recorded from the Burrum (Aptian-Albian) beds in Australia (Walkom, 1919: 30) and from Jurassic strata in many parts of both hemispheres (Seward, 1917: 524 et seq.). P. seymouricum is also similar to P. andersonii (Halle) and P. antarcticum (Halle) from the Jurassic of Grahamland. It is distinguished by the wide spacing of the pinnae, which are their own width apart as if forced apart by the insertion of the alternate pinnae on the rachis. It differs from the other New Zealand species, Ptilophyllum acutifolium Morris (middle Jurassic of Waikawa) in its venation and in the shape of its pinnae which are dilated at their bases and less tapering.