taxonID	type	description	language	source
0398C024720BD514FF6869684360F973.taxon	type_taxon	Type species. Echinocyamus nummuliticus nummuliticus Duncan & Sladen, 1884, p. 132, by original designation (Lambert & Thiéry 1914: 288). Emended diagnosis. Small fibulariids with an antero-posteriorly elongated periproct, and an apparent ringlike flange around the peristome made of slightly exaggerated bars just distal to the buccal pores.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD514FF6869684360F973.taxon	discussion	Remarks. This genus differs from the type genus Fibularia in having low ambulacral plates at the ambitus, an elongate periproct, and the interambulacra much narrower than the ambulacra, notably at the ambitus. Cyamidia nummulitica nummulitica tends also to have a lower overall test height to test length, but the applicability of this feature to all members of the genus Cyamidia will require full assessment of all the taxa ascribed to it by Duncan & Sladen (1884).	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD514FF686840414EFB5F.taxon	diagnosis	Emended diagnosis. Laganiform echinoids with internal buttresses reduced either to simple radiating partitions in all, or a subset of the interambulacra, or entirely lacking.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD512FF686B1C4391FAD8.taxon	description	Figures 4, 6. 1884 Echinocyamus nummuliticus Duncan & Sladen: 132 – 134, pl. 25: figs 14 – 20. 1914 C. [Cyamidia] nummulitica Duncan et Sladen (Echinocyamus) — Lambert & Thiéry: 288. Type material. Syntypes in the collection of the Geological Survey of India, Kolkata [not seen].	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD512FF686B1C4391FAD8.taxon	materials_examined	Material studied. NHM E 692, from Sind, Pakistan. Type locality. Several localities were listed by Duncan & Sladen (1884), but because none of the known specimens were selected as the name-bearing type, a type locality is likewise unknown. Type stratum. Kirthar Formation, Middle to Late Eocene (Jafa & Rai 1994; Rai 2007). ZooBank LSID. urn: lsid: zoobank. org: act: 6 A 8 F 5 B 2 A- 5 FE 2 - 400 B-AD 93 - D 7785 BBD 18 E 5	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD512FF686B1C4391FAD8.taxon	description	Description. Size and shape — Corona small, approximately 6 mm in TL; shape ovoid when viewed aborally; slightly flattened in profile, maximum height less than 50 % of TL. Internal buttressing — Absent. Apical system — Situated centrally, at the apex of the corona; monobasal, with four gonopores and a single central hydropore, not situated in a pit or groove; ocular pores are small and indistinct, lying well outside the area enclosed by the gonopores, almost directly between most proximal pores in each petal. Ambulacra — Ambulacral plating simple; ambulacra expanding distal to peristome to form fan-shaped array at least twice the width of interambulacra at ambitus; petals short, with 10 to 17 faintly conjugate respiratory pore pairs in each ambulacrum; pore pairs lying strongly oblique, crossing the ambulacral plates; distal pore pairs becoming even more strongly oblique with distance between pores in each pair slightly decreasing; width of interporiferous zones remaining largely constant along each paired petal, but increasing slightly at the distal end of the anterior, unpaired petal; petaloid region large, extending about 70 % of TL; food grooves absent; buccal pores large, facing obliquely towards the peristome; accessory pores situated in oblique patches in centres of plates, axis of patches angled towards perradial suture proceeding distally, apparently not along sutures; ambitus initiating at approximately seventh pair of ambulacral postbasicoronal plates. Interambulacra — Adapically, two unpaired plates lie in tandem adjacent to apical system; four or five postbasicoronal interambulacrals in each column visible in oral view; posterior unpaired interambulacrum expanding slightly in region accommodating periproct; a few scattered accessory pores visible near centres of some interambulacrals, particularly on the ambitus and oral surface. Tuberculation — Primary tubercles crenulate, perforate; approximately same diameter on oral and aboral surfaces, evenly distributed in ambulacra and interambulacra without differentiation into locomotory regions; miliary tubercles distributed among primaries. Peristome — Larger than periproct, about 13 % TL; infundibulum extremely shallow; peristomial opening facing directly downwards almost at midpoint of oral surface; framed by basicoronal circlet in which ambulacral plates are approximately same length as adjacent interambulacrals, although basicoronals are slightly longer around posterior half of peristome; 4 to 6 enlarged primary tubercles, areoles abutting, in each interambulacral area adjacent to peristome; in each ambulacrum, slightly elevated ridge or bar of stereom just distal to buccal pores, each bar extending slightly laterally from perradial bulge containing sphaeridium. Periproct — Small, approximately 10 % TL; facing downwards approximately halfway between posterior edge of peristome and posterior edge of the corona in oral view; distinctly elongated along anterior-posterior axis; bounded by first (5. a. 2, 5. b. 2) and second (5. a. 3, 5. b. 3) pairs of post-basicoronal plates. Perignathic girdle — Consisting of five small processes (auricles), one on internal surface of each interambulacral basicoronal. Sphaeridia — One per ambulacrum; fully enclosed; situated beneath distinct transverse bar just distal to buccal pores. Spines, pedicellariae, lantern — Unknown.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720BD512FF686B1C4391FAD8.taxon	discussion	Remarks. Duncan & Sladen (1884) distinguished three varieties (to be treated as subspecific taxa according to The Code) of Echinocyamus (= Cyamidia) nummulitica in addition to the form n. nummultica upon which we are basing our descriptions: C. n. obesa, C. n. oviformis and C. n. plana. These differ mainly in overall shape of the corona, particularly in terms of test height and degree of petaloid development. They might well represent valid species or subspecies, but this can only be clarified by re-examination of types, and analysis of intraspecific variation based on a large number of specimens. A fourth form described by Duncan & Sladen (1884), Echinocyamus rotundus, later placed in Cyamidia by Lambert & Thiéry (1914), may or may not represent a second species in the genus. It is based on a unique, worn specimen that, judging from the poor figures, does not show the typical peribuccal stereom bars observed in Cyamidia nummulitica. It does, however, appear to have the elongate periproct that seems to separate this genus from most other fibulariids.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720DD50EFF6869F143A4FACD.taxon	description	Figures 7 A – C, 8 – 9, 10 D, 11. 1962 Cyamidia paucipora Brunnschweiler: 162 – 164; fig. 1 A – D.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720DD50EFF6869F143A4FACD.taxon	materials_examined	Type material. GA CPC 2825 (holotype; Figs 7 A – C, 10 D). Material studied. In addition to the holotype, 7 “ topotypes ” (GA CPC 2826, 41767 – 41772) of Brunnschweiler (1962). Type locality. Sample M 24 from point 221 on airphoto No. 5170 on Run 2, Moogooloo Hill (hill crest located at 23 ° 36 ′ 12 ″ S, 114 ° 44 ′ 14 ″ E; exact coordinates of sampling locality unknown); about 8 miles SSE of the Pleiades Hills, Northwest Division, Western Australia. Type stratum. Merlinleigh Sandstone, Late Eocene (see Darragh & Kendrick 2010: pp. 24 – 25) ZooBank LSID. urn: lsid: zoobank. org: act: AC 48 DF 0 B- 22 B 0 - 4 ED 3 - AB 19 - 1 B 1 EBAFB 1799	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720DD50EFF6869F143A4FACD.taxon	description	Description. Size and shape — Corona very small, up to 3.5 mm in TL in material originally attributed to this species; outline distinctly oval (antero-posteriorly elongated) in aboral view; slightly flattened in profile, maximum height decreasing with size, being up to 70 % of TL in smallest and approximately 56 % TL in largest specimens. Internal buttressing — Absent. Apical disc — Situated centrally, at apex of corona; monobasal, with four gonopores and single hydropore which lies close to genital pore 2 and not situated in pit or groove; ocular pores small and located outside area enclosed by gonopores (Fig. 9 A); gonopores open in specimens as small as 2.55 mm, but may still be completely closed in slightly larger specimens (2.69 mm TL). Ambulacra — Plating not easily discernable, but ambulacra appear to expand towards ambitus; petals short, with up to five non-conjugate respiratory pore pairs in each ambulacrum; pore pairs strongly oblique, with obliqueness increasing distally; in small specimens with well-preserved surface detail, interporal areas raised, with glossy surface reminiscent of glassy tubercles, in slightly larger specimens this area is less raised but still appears to be composed of massive, unperforated stereom; interporiferous zones narrow and of constant width along petal; petaloid region large, extending about 60 % of TL; food grooves absent; buccal pores not visible in oral view, apparently lying close to peristome and facing horizontally into it; accessory pores crowded in small oblique clusters in centre of each plate; widespread isolated accessory pores present between these clusters, including in interporiferous zones; ambitus initiating at approximately fourth pair of ambulacral postbasicoronal plates. Interambulacra — Adapically, two unpaired plates lie in tandem adjacent to apical system (Fig. 10 D); basicoronal plates stout and quadrangular; ambital plating not discernable; a few scattered accessory pores present both in aboral and oral interambulacral plates. Tuberculation — Primary tubercles crenulate, perforate; homogeneously distributed on aboral surface; on oral surface, towards the peristome, tubercles up to 1.5 times larger and more widely scattered, separated by ridges bearing glassy tubercles and granules (Fig. 9 B); tubercles entirely missing on basicoronal plate of interambulacrum 5 and most of plate surface of plates 5. a. 2 and 5. b. 2; here large glassy tubercles are found instead (Fig. 9 C). Peristome — Relatively large, about 25 % TL; facing directly downwards; infundibulum shallow, but with down-turned, almost vertical lip; incomplete ring of slightly elevated ambulacral stereom bars framing peristome; distinct perradial bulge containing the sphaeridium in centre of each bar; in oral view, buccal pores are hidden by these bars. Periproct — Smaller than peristome, approximately 12 % TL; positioned inframarginally and facing obliquely down- / backwards in oral view; distinctly elongated along anterior-posterior axis; anterior end bounded by first pair of post-basicoronal plates (5. a. 2, 5. b. 2), other sutures not discernable. Perignathic girdle — Consisting of five small processes (auricles), one on each interambulacral basicoronal plate. Sphaeridia — One per ambulacrum; fully enclosed; situated beneath distinct transverse bar just distal to buccal pores. Spines, pedicellariae, lantern — Unknown.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C024720DD50EFF6869F143A4FACD.taxon	discussion	Remarks. Brunnschweiler (1962) established a new species for the specimens described above and attributed it to the genus Cyamidia on the basis of its elongate periproct and lack of internal buttressing. It was differentiated from previously described species of Cyamidia by its larger and more marginal periproct, the smaller number of petaloid pores and the glassy tubercles between the periproct and peristome. Brunnschweiler, however, did not take allometric growth into account. In most clypeasteroids, and indeed most echinoids, the periproct and peristome are proportionally larger in smaller specimens and the petaloid pore pair number is lower. The main difference from other Cyamidia species is therefore the presence of glassy tubercles between the periproct and peristome and the more marginal periproct (although periproct position too tends to change during early ontogeny). Cyamidia paucipora co-occurs with the larger species Lenicyamidia compta at the type locality. At first glance the two species appear very different — the former is very small, high, and ovoid in outline, while the latter is larger, more flattened and rounded. It also has a distinct oral tuberculation pattern. Upon closer examination, however, the two forms appear to be part of a single ontogenetic series, with the main differences being related to differential growth. Test height, for example, increases only slowly during growth (Fig. 11), causing the end members to look very different. When included in the same graph, specimens attributed to C. paucipora by Brunnschweiler (1962) fall along the same regression lines as L. compta. The size gap between C. paucipora and L. compta apparently led Brunnschweiler to believe that he was dealing with two different taxa. This discontinuity in the size distribution might have other reasons including, but not limited to: a) collection bias (the small specimens probably being picked from sieving residues, while the larger ones might have been hand-picked in the field); b) year-cohorts (many marine invertebrates reproduce only once annually, leading to different size cohorts within populations particularly among miniaturized, paedomorphic forms in which these size differences are exaggerated). The only other difference between C. paucipora and Lenicyamidia, apart from shape and pore pair number, is that in tuberculation pattern. However, the oral, medial area of glassy tubercles in Lenicyamidia can easily be derived from the corresponding area in Cyamidia paucipora. The latter also largely lacks spine-bearing tubercles, and features glassy ones in the oral, medial area instead (Fig. 9 C). Based on these observations, the two species are here considered synonymous and Lenicyamida compta is chosen as the senior synonym (Principle of the First Reviser; ICZN 1999 Art. 24.2).	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247211D50EFF6869FA4385F92D.taxon	type_taxon	Type species. Fibularia ovulum Lamarck, 1816 by ICZN Opinion 207 (1954: 350). Emended diagnosis. Small, occasionally almost spherical fibulariids entirely lacking internal buttresses; interambulacra very wide at ambitus, over 70 % width of ambulacra; ambulacral plates very high at ambitus, each plate almost as high as wide.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247211D50DFF686AEA4608FA90.taxon	description	Figures 1 – 2, 4, 12 1980 Tridium kieri Tandon & Srivastava: 1 – 3, pl. 1: figs. 1 – 6	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247211D50DFF686AEA4608FA90.taxon	materials_examined	Type material. Department of Geology, University of Lucknow, K 651 (holotype), K 652 – K 653 (paratypes). Material studied. DGUL: 10 specimens (K 654 – K 663), and numerous specimens without repository numbers; CASG: 4 specimens (72990, 72991); NHMW: 5 specimens (NHMW 2011 / 0420 / 0001 – 0005), all from type locality. Type locality. Near village of Guvar, Kachchh, India (23 ° 38 ′ 10 ″ N, 68 ° 32 ′ 30 ″ E). Type stratum. Nummulites beaumonti Zone of Tandon (1976), Middle Eocene. Other occurrences. Jhadwa (23 ° 30 ′ 30 ″ N, 68 ° 36 ′ 30 ″ E), Panandro (23 ° 41 ′ N, 68 ° 45 ′ 05 ″ E) villages and Ratchelo nala, 3.2 km south of Baranda village (23 ° 34 ′ 20 ″ N, 68 ° 43 ′ 10 ″ E), Kachchh, India. Emended diagnosis. Very small, almost spherical Fibularia unique among laganiforms in having only 3 gonopores, lacking gonopore in interambulacrum 2 position; infundibulum completely lacking, with peristomial region everted outwards until even with surrounding oral surface; buccal pores facing directly downwards, not into peristome; distinct circumoral ring proximal to buccal pores; periproct surrounded by slight, spout-like ridge; density of spine tubercles greatly reduced, only 2 to 4 primary tubercles found in tight grouping near centre of ambital plates; sutures of ambital plates smooth, lacking external structures such as spine or pedicellaria tubercles or glassy tubercles. ZooBank LSID. urn: lsid: zoobank. org: act: 8 AC 353 E 9 - 96 E 0 - 4274 - BC 94 - 561 CC 0 AA 8130	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247211D50DFF686AEA4608FA90.taxon	description	Description. Size and shape — Corona small, largest specimens not exceeding 5 mm TL; corona globular, almost spherical, with barely subequal length, width and height; aboral outline nearly circular, very slightly acuminate posteriorly; profile of corona likewise circular, very slightly flattened adorally in peristomial region. Internal buttressing — Absent. Apical system — Central in aboral view; monobasal, with three gonopores, lacking gonopore in interambulacral position 2; gonopores well within madreporic plate; single, central hydropore, opening flush with plate surface, not in pit or groove; ocular pores small and indistinct, almost directly between most proximal pores in each petal. Ambulacra — Ambulacral plating simple; petals short, consisting of 4 to 6 large, faintly conjugate respiratory pore pairs in each ambulacrum; pore pairs lying strongly oblique, crossing ambulacral plates; distal pore pairs becoming even more strongly oblique with distance between pores in each pair slightly decreasing; width of interporiferous zones remaining largely constant in adapical two thirds of each petal, but decreasing slightly towards distal end; distally, obliqueness of pore pairs increases so that most distal pore pairs are oriented almost parallel to radius; in some adapical pore pairs, outer pore pierces interambulacral plate rather than ambulacral; petaloid region large, extending almost 70 % of TL in aboral view; buccal pores large, facing downwards rather than into the peristome; accessory pores small, barely larger than openings in stereom meshwork; usually crowded in patches around large tubercles in middle of plates; except for very well-preserved specimens, pores only visible close to peristome; food grooves absent. Interambulacra — Adapically, two unpaired plates lie in tandem adjacent to apical system; four, occasionally five post-basicoronal interambulacrals in each column visible in oral view; interambulacrum 5 not expanding in region accommodating periproct, but continuously divergent in oral view; a few scattered accessory pores visible in some interambulacrals; at ambitus, interambulacra at least as wide as ambulacra; each column comprising large, hexagonal plates of equal height and width. Tuberculation — Patchy and sparse, with 1 to 4 tubercles concentrated in small clusters separated from tubercles in adjacent plates by areas of unornamented stereom; areoles wide, approximately three times diameter of boss, slightly sunken; miliary tubercles indistinct, although small tubercles about 20 % diameter of the primary tubercles likely represent miliaries, or perhaps attachment points for pedicellariae; glassy tubercles absent. Peristome — Small, approximately 17 % TL; circular; facing directly downwards almost centrally on oral surface but slightly displaced approximately 1 – 2 % TL posteriorly; opening not sunken, lacking infundibulum; rimmed by sharp, raised ridge of relatively dense stereom forming circumoral ring; framed by basicoronal circlet in which ambulacral plates are approximately same length as adjacent interambulacrals; 4 to 6 enlarged primary tubercles, areoles abutting, in each interambulacral area adjacent to peristome; in each ambulacrum, slightly elevated ridge or bar of stereom just distal to buccal pores, extending only slightly laterally from perradial bulge containing sphaeridium. Periproct — Small, about 13 % TL; subcircular to subpentagonal in outline, sometimes slightly anteroposteriorly elongated; facing downwards halfway between peristome and posterior margin; bounded by first (5. a. 2, 5. b. 2) and second (5. a. 3, 5. b. 3) pairs of post-basicoronal plates; margin of periproct very slightly raised into slight " spout ". Perignathic girdle — Consisting of five small processes (auricles), one on the internal surface of each interambulacral basicoronal. Sphaeridia — One per ambulacrum; fully enclosed; situated beneath low transverse bar just distal to buccal pores. Spines, pedicellariae, lantern — Unknown.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247211D50DFF686AEA4608FA90.taxon	discussion	Remarks. In the original description Tandon & Srivastava (1980: fig. 2) showed the third pair of postbasicoronal plates forming part of the periproctal margin, but this was not in agreement with their own description in the text. We were able to determine that the third pair of post-basicoronals plays no part in the construction of the periproctal margin. In addition, Tandon & Srivastava (1980: fig. 2) depicted a small plate just distal to each ambulacral basicoronal, which in turn suggested that the ambulacral basicoronals were significantly shorter than the interambulacral basicoronals, causing the ambulacral basicoronals to be isolated from the adjacent interambulacral first post-basicoronals in every case. However, these small, additional plates are not apparent from our observations. In fact, the ambulacral basicoronals are nearly equal in length to the interambulacral basicoronals. The ambulacral basicoronals are in contact with the adjacent interambulacral first post-basicoronals in nearly every radius, as in other fibulariids. The illustration in Tandon & Srivastava (1980: fig. 1) also shows the outer pores of the petals not piercing the interambulacra, but we have identified several outer pores proximal to the apical system that emerge through the interambulacrals. Tandon & Srivastava (1980) and Smith & Kroh (2011) identified the presence of just three gonopores as the sole autapomorphy of the genus, thereby distinguishing it from Fibularia. We have identified several other features that are autapomorpic in T. kieri (see diagnosis above), but these unique, phylogeneticially uninformative features do not serve to distinguish T. kieri from Fibularia in a cladistic sense, and we here consider Tridium a junior synonym of Fibularia. Smith & Kroh (2011) additionally questioned whether three gonopores were consistent in larger populations. Genital pore 2, however, is missing in all known specimens (N> 350) and it is unlikely that this is a case of abnormal development. Except in rare cases of specimens obviously affected by sublethal predation or other growth deformations, gonopore development is usually consistent within clypeasteroid species and not prone to variation. Curiously, Tandon & Srivastava (1980: p. 2) indicated that " no female was found ". Sexual dimorphism in clypeasteroids, and even in micro-echinoids such as Fibularia plateia, F. cribellum, and F. japonica, is known from differences in gonopore diameter and sometimes even from the presence of brood pouches, as in F. nutriens. However, Tandon & Srivastava (1980) made no such measurements. It is most likely that this species exhibits no readily detectable sexual dimorphism than the rather low likelihood that there were no females represented in the over 350 specimens collected. Re-examination of Fibularia kieri shows that the missing gonopore is not the sole autapomorphy of that taxon. The patchy tuberculation, with concomitant lack of ornamentation in proximity to the plate sutures, and especially features of the peristomial region are very different from what is usually observed in fibulariids or in other echinoids in general. The most adoral tubercles usually support spines that are internally directed towards the mouth in the centre of the peristomial membrane, more or less parallel or at low angles to the surface of that membrane. Likewise, the buccal podia (and the pores supporting them) are directed towards the mouth in most clypeasteroids, so that the podia can more easily reach into it (Mooi 1986). In F. kieri, the situation is quite different. Here the adoral tubercles and buccal pores face downwards rather than towards the peristome. The tubercles would have supported spines that extended at right angles to the test and to the plane of the peristomial membrane. Unless they were significantly bent inwards, they would not have formed a grill across the membrane as seen in other clypeasteroids. In addition, the buccal podia would have been well situated to reach downwards at right angles to the test, but not into the mouth region. A peristomial infundibulum, observed in almost all other clypeasteroids, is lacking, giving the peristomial region a flat aspect flush with the surrounding corona. The entire organization has the appearance of having been everted, or “ turned outwards ” (Fig. 4). The function of the inner circumoral ring is unclear. In comparison with taxa in which the infundibulum is not everted, the position of the ring would correspond to the line of insertion of the peristomial membrane. No similar structure has been observed in other clypeasteroids. A superficially similar ring is developed in Leniechinus and Cyamidia, but this lies more distally, aboral to the buccal pores. In these taxa, this outer ring is formed by lateral expansion of the ambulacral bars overlying the sphaeridia. In Tridium these are slightly expanded laterally as well, but fail to meet interradially, being separated by wide gaps across the interambulacra.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50DFF6869BE46D3F91B.taxon	type_taxon	Type species. Lenicyamidia compta Brunnschweiler, 1962, p. 165, by original designation. Emended diagnosis. Small fibulariids with an antero-posteriorly elongated periproct, and a distinct naked medial zone on the oral surface, with the tubercles bilaterally arranged left and right of it.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50DFF6869BE46D3F91B.taxon	discussion	Remarks. Like Cyamidia this taxon differs from the type genus Fibularia in having low ambulacral plates at the ambitus and an elongate periproct. It differs from Cyamidia mainly by its distinctive oral tuberculation, which is similar to that seen in Leniechinus, Lenita, and some cassidulids. In contrast to the former two, however, the enlarged tubercles are not distinctly invaginated, but have only moderately sunken areoles.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50BFF686B34438CF872.taxon	description	Figures 4, 7 D – F, 10 A – C, 11, 13 – 14. 1962 Lenicyamidia compta Brunnschweiler: 165 – 169, figs 2 – 3. 1966 Lenicyamidia compta Brunnschweiler — Philip: 116 – 117, fig. 1.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50BFF686B34438CF872.taxon	materials_examined	Type material. GA CPC 2827 (holotype, Figs 7 D – F, 10 B) and GA CPC 2828 (paratype). Material studied. GA CPC 2827 – 2829, 41773 – 41799. Type locality. Sample M 24 from point 221 on airphoto No. 5170 on Run 2, Moogooloo Hill (hill crest located at 23 ° 36 ′ 12 ″ S, 114 ° 44 ′ 14 ″ E; exact coordinates of sampling locality unknown); about 8 miles SSE of the Pleiades Hills, Northwest Division, Western Australia. Type stratum. Merlinleigh Sandstone, Late Eocene (see Darragh & Kendrick 2010: pp. 24 – 25) ZooBank LSID. urn: lsid: zoobank. org: act: 90041316 - 5191 - 4933 - A 119 - 6 C 0 E 598 DD 5 D 2	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50BFF686B34438CF872.taxon	description	Description. Size and shape — Corona small, not exceeding 10 mm in TL among available specimens; outline in aboral view forming slightly angular circle; distinctly flattened in profile, maximum height between 30 and 40 % of test length. Internal buttressing — Absent, but ambulacral plates bear large pits internally and are about half as thick as interambulacral plates in their centre (Fig. 14 C), explaining peculiarly shaped internal casts (Fig. 14 C) reported by Brunnschweiler (1962: fig. 2 E); pits associated with pores for accessory tube feet (Fig. 14 B). Apical system — Situated centrally, at apex of corona; monobasal, with four gonopores and single central hydropore, not situated in pit or groove; ocular pores small and indistinct, lying well outside area enclosed by gonopores. Ambulacra — Ambulacral plating simple; ambulacra expanding only slightly towards ambitus where they are barely wider than interambulacra; petals short, with up to 21 non-conjugate respiratory pore pairs in each ambulacrum; pore pairs strongly oblique, crossing ambulacral plates; interporal ridge smooth and formed by unperforated stereom; distal pore pairs becoming even more strongly oblique with distance between pores in each pair slightly decreasing; width of interporiferous zones widest halfway along petals and becoming slightly narrower again distally; petaloid region large, extending about 70 % of TL; food grooves absent; buccal pores large and located close to peristomial edge, facing horizontally into peristome, externally visible only in broken specimens (Fig. 14 E) since they are hidden by transverse stereom bars in oral view; accessory pores evenly distributed all over test on aboral surface (including interporiferous zones and interambulacral plates), but forming patches obliquely crossing ambulacral plates and less common elsewhere on oral surface; ambitus initiating at approximately fourth to fifth pair of ambulacral postbasicoronal plates. Interambulacra — Adapically, two unpaired plates lie in tandem adjacent to apical system; three or four postbasicoronal interambulacrals in each column visible in oral view; posterior unpaired interambulacrum expanding distinctly in region accommodating periproct; basicoronal plates usually extending only to first adjacent ambulacral plate, except in interambulacrum 2, where usually extending to second adjacent ambulacral plate on one or both sides; in largest specimen with plate sutures visible (CPC 41796), basicoronal plates of interambulacra 1, 3 and 4 also extend on one side to second adjacent ambulacral plate due to presence of large spine-bearing tubercles on margins of these plates (usually missing in smaller specimens) and fact that sutures are curved to make room for tubercles slightly modifies plate outline in such a way that they come into contact with second ambulacral plates; accessory pores evenly spread over aboral interambulacra, but less common, though present on oral interambulacral plates. Tuberculation — Primary tubercles crenulate, perforate, homogeneously distributed on aboral surface; on oral surface, in contrast, there is a narrow area between the periproct and peristome (Fig. 14 D), as well as anterior of the latter (Fig. 14 A), free of primary tubercles; instead densely covered with glassy tubercles; lateral to this medial area are located primary tubercles with slightly sunken areoles, these tubercles larger than aboral tubercles. Peristome — Larger than periproct, about 18 % TL; infundibulum extremely shallow but with near-vertical walls; peristomial opening facing directly downwards almost at midpoint of oral surface; framed by basicoronal circlet in which ambulacral plates only slightly longer than adjacent interambulacrals; plates of basicoronal circlet distinctly longer in posterior half of test; only scattered single tubercles present on interambulacral basicoronals adjacent to peristome, mainly on larger specimens; peristome framed by broken circle of circumferential bars overlying sphaeridial chambers (Fig. 14 E). Periproct — Small, approximately 12 % TL; facing down- and slightly backwards; located close to posterior margin on oral side; distinctly elongated along anterior-posterior axis; bounded by first (5. a. 2, 5. b. 2), second (5. a. 3, 5. b. 3), and one plate (5. b. 4) of the third pair of post-basicoronal plates. Perignathic girdle — Consisting of five small processes (auricles) attached to the internal surface of each interambulacral basicoronal; on their adoral side a pair of minute depressions (likely muscle scars for insertion of lantern protractors) located in each interambulacrum. Sphaeridia — One per ambulacrum; fully enclosed (Figs 4, 14 E); situated beneath distinct transverse bar just distal to buccal pores. Spines, pedicellariae, lantern — Unknown.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247212D50BFF686B34438CF872.taxon	discussion	Remarks. Brunnschweiler (1962) illustrated the apical disc as being composed of four genital plus an additional central plate. However, Philip (1966) showed that the apical disc was of typical clypeasteroid monobasal structure. The illustration of an “ internal mold ” by Brunnschweiler (1962: fig. 3) in reality represents an internal view of the oral surface (and thus shows a mirror image of the outside plating pattern). This accounts for the apparent deviation from Lovén’s Rule in his drawing. The peristomial region of L. compta is markedly different from that of other fibulariids studied here (Fig. 4). There are no clusters of tubercles on interambulacral basicoronals, the sides of the peristomial infundibulum are very steep and the circumferential stereom bars are very close to the peristomial edge, almost overhanging it in some cases. The oral tuberculation of Lenicyamidia was compared with that of Lenita by Brunnschweiler (1962). While both possess a medial zone free from spine-bearing tubercles, there are two obvious differences: 1) in Lenita the tubercles have deeply incised, asymmetrical areoles (these are shallow and near symmetrical in Lenicyamidia); and 2) large glassy tubercles are lacking in this zone in Lenita. It seems likely, therefore, that this tuberculation pattern is not homologous, but has adaptive significance causing it to have arisen independently in several neognathostome clades. In addition, Lenita, which is an early scutelline, differs in many other respects, including possession of biserial interambulacra at the apex, paired basicoronals, and other features not found in laganiforms. In contrast, Lenicyamidia, is clearly a laganiform, having two uniserial plates in the adapical interambulacra and a basicoronal circlet typical of fibulariids.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
0398C0247217D509FF686A0047CFFD4F.taxon	discussion	In the genus-level analysis based on the Kroh & Smith (2010) dataset, branching order within the fibulariids is poorly resolved. When Lenicyamidia was excluded, Leniechinus was recovered as a sister group to Fibularia + Tridium in an unresolved trichotomy with Cyamidia (Fig. 3). However, in the species-level analysis, Leniechinus falls to the base of the fibulariid clade, below the nodes joining Echinocyamus and Mortonia to the more crownward fibulariids (Fig. 5). The reason for this discrepancy is based on the observation that more features could be scored for the extant taxon Echinocyamus than for the incompletely known fossil taxon Leniechinus in the genus-level analysis. Moreover, in the species-level analysis several features that turn out to be relatively plesiomorphic within the Fibulariidae overall push Leniechinus more basally. For example, the relatively high number of pore pairs in the petaloids, along with the width of the interporiferous zones, tend to exclude Leniechinus from the more crownward fibulariids, making it plesiomorphically more similar to Mortonia. Kier (1968) stated that Leniechinus was likely more closely related to Lenita than to other fibulariids such as Lenicyamidia, based at least in part on the presence of internal buttresses (which are lacking in Lenicyamidia). Internal buttresses can be greatly reduced in paedomorphic scutellines so that they resemble those of fibulariids. Mooi (1990) excluded Lenita from his concept of the laganines. Nearly all the characters he listed as synapomorphies for the scutellines cannot be determined in Lenita. Nevertheless, Lenita is neither a laganine nor a clypeasterine, as it clearly lacks laganiform synapomorphies. In Lenita, the interambulacral columns plesiomorphically remain paired all the way to the apical system, the hydropores are numerous and scattered across the madreporite (seen in laganiforms only in taxa such as Peronella), and the periproct is strongly aboral, separated from the peristome by at least three pairs of post-basicoronal plates. Lenita also expresses key features in the symmetry of the oral surface plating that are also very unlike those of laganiforms. In contrast, the present analysis firmly places Leniechinus among the laganiforms. For these reasons, Leniechinus cannot be considered closely related to Lenita. Similarities in oral tuberculation between Lenita and Leniechinus (the supposed locomotory tubercles) appear to be convergent. Lenicyamidia compta, on the other hand, does have affinities with fibulariids. It possesses key features that place it crownward in the fibulariid clade, even above the nodes that join Leniechinus, Mortonia, and Echinocyamus to the family (Fig. 5). It has reduced petaloids, narrow interporiferous zones, and completely lacks internal buttresses. Among all the fibulariids, the elongate periproct and test plate pattern places it with Cyamidia.	en	Mooi, Rich, Kroh, Andreas, Srivastava, Dinesh K. (2014): Phylogenetic re-evaluation of fossil and extant micro-echinoids with revision of Tridium, Cyamidia, and Lenicyamidia (Echinoidea: Clypeasteroida). Zootaxa 3857 (4): 501-526, DOI: http://dx.doi.org/10.11646/zootaxa.3857.4.3
