Rintoulia pectinata (Hector) McLoughlin, Tosolini, Nagalingum, and Drinnan, 2002

Pole, Mike, 2019, Middle-Late Jurassic plant assemblages of the Catlins coast, New Zealand, Palaeontologia Electronica (a 51) 23 (3), pp. 1-48 : 19-20

Rintoulia pectinata (Hector) McLoughlin, Tosolini, Nagalingum, and Drinnan, 2002

Figure 11

1886 Lomarites pectinata Hector , fig. 30A (5).

1917 Microphyllopteris pectinata (Hector) Arber , p.

40, pl. 7, figs. 3, 4, 6, 8, 10, 11.

1919 Microphyllopteris pectinata (Hector) ; Walkom, p. 186, pl. 8, figs. 1, 4.

1981 Pachydermophyllum pinnatum (Walkom) Retallack , p. 176.

2002 Rintoulia pectinata (Hector) McLoughlin, Tosolini, Nagalingum, and Drinnan.

Material. Curio Bay: LX1233, LX1238, Little Beach-03: LX1021, LX1029, Owaka: LX669.

Description. Frond elongate,> 30 mm long. Axis 1–1.7 mm diameter. Pinnules semicircular or ovate, attached by complete base to rachis, 1–5 mm long, 2–4 mm wide, separated by 0.5–1.0 mm.

Remarks. The ‘saga’ of this morphology highlights issues of trying to deal with fossils that have neither fertile structures nor cuticle. In this case the basic morphology has been attributed not only to several families of ferns, but also to gymnosperms. Arber (1917) considered that some New Zealand material would be “unhesitatingly” referred to Gleichenites by “most authors.” To him there was no doubt that the fossils were ferns and related to present-day Gleicheniaceae . But he regarded Gleichenites as a genus that was “incapable of being defined compactly and concisely.” He therefore introduced a new genus, Microphyllopteris , for fronds that had (among other characters) pinnules “very small, subcircular or ovate, closely set, broadest at the base, and attached by their whole base.” There was evidently a little uncertainty in his own mind at the generic limits of Microphyllopteris . He remarked on a specimen that he described as Microphyllopteris sp. from Owaka, that “It is possible that this specimen should be more correctly referred to the genus Thinnfeldia , though I am inclined to regard it as an example of Microphyllopteris , on account of the small size of the pinnules.” Arber (1917) then identified three species of Thinnfeldia (a gymnosperm) from Owaka, T. lancifolia , T. feistmanteli , and T. odontopteroides . There are probably intergradations of these Owaka ‘species’, and possibly with Microphyllopteris as well. Edwards (1934) suggested that some of Arber’s (1917) Microphyllopteris pectinata may even be Cladophlebis reversa . Since then, Doludenko (1971) and Doludenko et al. (1998) have placed Thinnfeldia into synonymy with Pachypteris .

Retallack (1981), placed several of Arber’s (1917, p. 40, pl. 2, fig. 10, pl. 7, figs. 3, 4, 6, 8, 10, 11 only) specimens of Microphyllopteris pectinata into Pachydermophyllum (as Pachydermophyllum pinnatum (Walkom) Retallack ), a genus explicitly including cuticular details in its definition (Thomas and Bose, 1955). However, McLoughlin et al. (2002) subsequently placed most of Arber’s specimens into Rintoulia pectinata (Hector) McLoughlin, Tosolini, Nagalingum, and Drinnan. They excluded two specimens (Arber, 1917, pl. 7, figs. 5 and 9), which are at least twice pinnate. These two specimens compare with Archangelskya .

Nagalingum and Cantrill (2006) proposed that Gleichenia -like fern fronds should be classified in two genera: Gleicheniaceaephyllum , if they could be referred to the Gleicheniaceae , or Microphyllopteris , “for ferns that cannot be ascribed conclusively to Gleicheniaceae .” Microphyllopteris was then considered by Miller and Hickey (2008), who emended its diagnosis and suggested its use be restricted to true gleicheniaceous fronds.

Vera and Passalia (2012) argued that Microphyllopteris is illegitimate, as the type material had been reassigned by Rettalack (1981). They introduced a new fern genus Korallipteris , stating: “… since [ Microphyllopteris ] cannot be used for fossil

POLE: CATLINS COAST JURASSIC ferns, we propose Korallipteris nov. gen. as a ‘‘replacement.”

Underlying much of this debate is an issue of intent – whether the material is thought to be a fern or a pteridosperm. In a strict sense, Microphyllopteris appears to have clear priority for material with semicircular pinnules, but which is sterile, has no cuticle, and higher affinities that are not known. However, in the interests of some stability, Rintoulia is used for the Catlins material, following McLoughlin et al. (2002).

Based on this concept of Rintoulia , it is common in both the Jurassic (Walkom, 1919, 1921; Jansson et al., 2008) and Early Cretaceous (White, 1961; Douglas, 1969; McLoughlin et al., 2002) of Australia and also appears to be present in the Lower Cretaceous of India (Sah, 1965; Bose and Sah, 1968). Note that on the basis of spores, the Gleicheniaceae were clearly present in the New Zealand Mesozoic (Raine, 2011).

Figures

FIGURE 11. Rintoulia pectinata 1. LX1029, Little Bay-03; 2. LX1021, Little Bay-03; 3. LX669, Owaka. All scale bars equal 10 mm.