142 



J.B. RICHARDSON, R.M. RODRIGUEZ AND S.J.E. SUTHERLAND 



Occurrence. Lower and Middle San Pedro Formation, RS and H 

 Biozones; Upper Ludfordian and Lower Pridoli, possibly some 

 specimens are reworked. 



Subturma ZONOTRILETES Waltz 1935 in Luber & Waltz 1938 



Infraturma CRASSITI Bharadwaj & Venkatachala 1961 



Genus AMBITISPORITES Hoffmeister 1959 



Ambitisporites warringtonii (Richardson & Lister, 1 969) 

 comb. nov. 



Basionym. Retusotriletes warringtonii Richardson & Lister 1969. 



1969 Retusotriletes warringtonii Richardson & Lister 1969: pi. 

 37, figs 7, 8. 



Remarks. The curvaturae are thickened and form a crassitude that 

 is more or less coincident with the equator. These forms are closely 

 similar to A. avitus except for the size and thickness of the crassitude. 



Ambitisporites? eslae (Cramer & Diez, 1975) comb. nov. 

 PL 5, fig. 1 



Basionym. Retusotriletes eslae Cramer & Diez 1975 {pars). 343, 

 pi. 1, fig. 11 only. 



1973 Ambitisporites sp. B, Richardson & loannides: 277, pi. 6, 



fig. 8 only. 

 1975 Retusotriletes eslae Cramer & Diez (pars): 343, pi. 1, fig. 

 1 1 only (see discussion under Scylaspora elegans sp. nov.). 

 71976 Retusotriletes maculatus McGregor & Camfield: 26, pi. 1, 



fig. 6. 

 71995 Ambitisporites tripapillatus Moreau-Benoit; Burgess & 

 Richardson: 16, pi. 6, fig. 16. 



HOLOTYPE. Cramer & Diez 1975: pi. 1, fig. 1 1. 



Comparison and remarks. A. tripapillatus Moreau-Benoit 

 (1976: 37, pi. 7, figs 2-A) has a darkened area along the Y-rays at the 

 spore apex with straight to concave sides. Scylaspora elegans has a 

 large darkened apical area and proximal rugulate sculpture. 

 Retusotriletes maculatus McGregor & Camfield (1976) and, in part, 

 Awfe/Y/s/^onYe^sp.B (McGregor & Camfield, 1976: pi. 6. fig. 8 only), 

 appear to have a narrow equatorial crassitude, but are otherwise 

 similar to A. eslae (Cramer & Diez). They all show an equatorial 

 crassitude except at the radial apices where the curvaturae invagi- 

 nate. A similar feature is seen in some specimens of Ambitisporites, 

 eg. A. avitus. Several Lower Devonian laevigate spores are proxi- 

 mally retusoid (McGregor & Camfield, 1976) and from the limited 

 data available these spores appear to be pandemic, although many of 



the records are from Spain, North Africa and South America. The age 

 of similar spores to this species is varied. A. eslae, A. tripapillatus 

 and R.. maculatus are all from the Lower Devonian but the Burgess 

 & Richardson record is of Lower Rndoli age. 



Occurence. Argovejo, EC (a) subzone and MN zone (Lower 

 Lochkovian). 



Genus SCYLASPORA Burgess & Richardson 1995 



Type species. Scylaspora scripta Burgess & Richardson 1995. 



Remarks. Some of the spores placed in the genus Rugosisporites 

 by Dufka (1995) resemble those of Scylaspora; however, the type 

 species of Rugosisporites is Retusotriletes chartulatus McGregor 

 (1978) which is retusoid with distinct invaginations at the radial 

 apices. McGregor's species is similar, but not identical, to some 

 Middle and Upper Devonian species also placed in the genus 

 Retusotriletes. namely R. rugulatus and R. phillipsii. Consequently, 

 since the type species of Rugosisporites is regarded here as belong- 

 ing to Retusotriletes. as McGregor determined, then removal of the 

 type species necessitates the invalidation of the genus Rugosisporites 

 by placing it in synonymy with the genus Retusotriletes. 



Scylaspora elegans sp. nov. PI. 5, figs 2-4, PI. 6, fig. 8 



1975 /?er((5(7rn7(?fe.j e.v/oe Cramer & Diez (pars): 343, pi. l,fig. 12 



only. 

 1983 Retusotriletes eslae Cramer & Diez; Rodriguez, 1983: 47, 



pi. 5, figs 14, 19,20. 



Holotype. FM 1490 (PI. 5, fig. 2), diameter 43 pm: sample La Vid 

 13, slide D3/2, co-ord. 090 1036; E.F. no. J34/3; upper San Pedro 

 Formation, La Vid section, Cantabrian Mountains, Province of Leon, 

 northwest Spain. 



Derivation of name. Latin a. elegans, refined, elegant, referring 

 to the delicate proximal sculpture. 



Diagnosis. A Scylaspora with a narrow +/- equatorial curvatural 

 crassitude, three distinct proximal inter-radial papillae, Y-sutures 

 bordered by darkened (?thickened) narrow areas tapering to the 

 equator, proximal surface with contorted microrugulae, accompan- 

 ied by short radial microrugulae near the curvaturae, microrugulae 

 become less distinct polewards; distal exine laevigate. 



Description. Amb rounded to subtriangular. Proximal surface 

 with straight to sinuous microrugulae adjacent to the curvaturae, 

 <0.5 |jm wide and high, and decreasing in height towards the 

 proximal pole; straight microrugulae confined to the curvatural area. 

 Under the SEM the microrugulae are close-packed and contorted 



PLATE 5 



Fig. 1 Ambitispohtesl eslae (Cramer & Diez) comb. nov. FM 1505. Arg92/12 (510) 3, 206 1 169. 



Figs 2-4 Scylaspora elegans sp. nov. 2, FM 1490 (holotype). proximal view showing dark apical triangle, narrow crassitude, curvaturae perfectae and 



inter-radial papillae. LV92/13 (D3) 2, 0901036; 3a, 3b, FM 1506, 3b, x 1500 showing minute radial ridges outside the curvatural crassitude. Ger92/12 



(371) 3, 100 1 131; 4, FM 1507. LV92/17 (D3) 3, co-ord. 207 0908, E.FV21/3, 

 Figs 5-8 Scylaspora vetusta (Rodriguez) comb. nov. showing variations. 5, FM 1508, oblique compression showing +/- radial muri around the curvatural 



crassitude, LV92/8 (D3) 2, 106 0991; 6, FM 1509, proximal view, thin-walled specimen showing equatorial radial thickenings becoming indistinct 



towards the proximal pole, LP92/8 (D2) 1,025 IOI4;7a-c,FM 1510, proximal view showing irregular and anastomosing proximal muri; 7c. x 1500; 



LV92/8 (D3) 2, 058 1 127; 8, FM 151 1, specimen showing paired lips, Arg92/5a (473) 3. 029 0910. 

 Fig. 9 Scylaspora cf. scripta Burgess & Richardson 1995. FM 1512, x 1500, LV97/8a (D16) 2, 096 1 123. 

 Fig. 10 Scyta.spora ci. kozlica (DufkA) comb. nov. FM 1513, LV92/8 (D3) 1, 163 0983; 10a, proximal polar compression, showing proximal microrugulae 



and grana; 10b, x 1500, showing detail of proximal sculpture. 



All figs X 1 000, unless stated otherwise. 



I 



