Elatocladus confertus (Feistmantel, 1877)

Pole, Mike, 2019, Middle-Late Jurassic plant assemblages of the Catlins coast, New Zealand, Palaeontologia Electronica (a 51) 23 (3), pp. 1-48 : 24-27

Elatocladus confertus (Oldham and Morris) Halle, 1913

Figure 16

1886 Taxites matai Hector , fig. 30 (5).

1913 Palyssia conferta Arber , p. 346, pl. 8, fig. 5.

1913 Elatocladus conferta Halle , pl. 8, figs. 26–40.

1917 Elatocladus confertus (Oldham and Morris)

Halle; Arber, p. 58, pl. 1, figs. 1, 3, pl. 6, fig. 4,

pl. 8, fig. 6.

1989 Elatocladus confertus (Oldham and Morris)

Halle; Gee, p. 201, pl. 8, fig. 75.

2004 Elatocladus confertus (Oldham and Morris)

Halle; Rees and Cleal, pl. 18, figs. 5, 6.

Material. Blue Cod Bay : LX0678, LX1147, LX1148, Curio Bay: LX1090, LX1102, LX1107, LX1169, Little Beach-01: LX0677, LX1050, LX1053, LX1055, LX1057, LX1058, LX1060, Otara-21: Noted in field, Otara-34: LX0686, Otara-31: LX0687, Otara-32: LX0694, Otara-33: LX0713, The Chasm: LX0661 LX1175, LX1176.

Description. Branching shoots> 80 mm long, with spirally inserted leaves on 1–2 mm diameter stem, distichously flattened. Around 6–8 leaves per 10 mm of stem, margins of adjacent leaves touching, or less than 0.5 mm apart. Leaves 6–9 mm long, 1.2–1.7 mm wide, bifacially flattened, falcate (reflexed, with mid portion of leaf arching apically), very elongate ovate, or with parallel margins in the middle, apices acute to rounded, base narrowed to a short false petiole, decurrent on stem, univeined, with vein running to apex.

Remarks. This is the most widespread conifer foliage type of the Catlins Coast Jurassic. Gee pointed out that Elatocladus confertus has reflexed leaves, and that this is a “fairly consistent character” to distinguish E. confertus from other Elatocladus species. Gee (1989), in her work on the Hope Bay material, clarified some of the characters present in these, or similar forms, and provided a key. This provides a basis to confirm the older New Zealand identifications and perhaps see if new species are present. One has thin, straight, narrow leaves, placed into E. planus . On the basis of epidermal information Townrow (1967) described a new taxon, Mataia podocarpoides , with affinities to Podocarpaceae , for a range of E. confertus material (the extant New Zealand conifer Prumnopitys spicata , Podocarpaceae , with Maori name ‘matai’, has similar foliage). The type locality was nominated as the Jurassic Clent Hills. However, there is no cuticular preservation there, and epidermal details come from material in the Upper Cretaceous strata in the Malvern Hills, New Zealand and from the Jurassic Walloon Coal Measures in Queensland, Australia (Note the error in Pole, 2009, where the cuticle was stated to come from the Clent Hills). The Catlins material may well be M. podocarpoides , but Mataia should be restricted to material with epidermal details. The E. confertus morphology has clearly been produced by various taxa (Frenguelli, 1949; Rao, 1964; Bose et al., 1982) and Podocarpaceae has been suggested as the affinity. In the Catlins Jurassic, given the common occurrence of permineralised wood with a structure consistent with Podocarpaceae (Crié, 1889; Arber, 1917; Edwards, 1934) and the common occurrence of broadly podocarpaceous pollen (Thorn, 2001; Raine et al. 2011) Podocarpaceae would seem likely. Edwards (1934) hinted at Elatocladus foliage being attached to a Palissya , a reproductive structure seeming more certainly coniferous, but with still unclear family affinities (Pattemore and Rozefelds, 2019, see below). On these grounds, the affinities of E. confertus remain open, and it is not placed here into any family here.

Figures

FIGURE 16. Elatocladus confertus 1. LX1060, Little Bay-01; 2. LX0674, Little Bay-01; 3. LX1050, Little Bay-01; 4. LX1057, Little Bay-01; 5. LX1107, Curio Bay; 6. LX1147, Blue Cod Bay; 7. LX1090, Curio Bay. All scale bars equal 10 mm.