Parasmittina agathae Hayward & Parker 1994
| Main Authors: | Martino, Emanuela Di, Taylor, Paul D. |
|---|---|
| Format: | info publication-taxonomictreatment |
| Terbitan: |
, 2018
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/3799556 |
Daftar Isi:
- Parasmittina agathae Hayward & Parker, 1994 (Figs 71–76; Table 16) Smittia spathulata: Kirkpatrick, 1890: 619, pl. 17, fig. 1. Parasmittina agathae Hayward & Parker, 1994: 55, fig. 1A–F. Figured material. RGM.1350562, Holocene, UPGG 041, off South Sulawesi. Description. Colony encrusting, multiserial, multilaminar. Autozooids irregularly arranged, rectangular to irregularly polygonal, distinct by narrow sutures, longer than wide (mean L/W = 1.59). Frontal shield flat to slightly convex, coarsely nodular, outlined by a single row of marginal areolar pores, circular to oval, 20–40 μm long. Primary orifice broader than long, about 65 μm long by 80 μm wide, apparently with a coarse denticulation on the distal edge; lyrula robust, broad, occupying about half width of the proximal orificial edge, trapezoidal; condyles pointed, downwardly directed. Two distal oral spine bases visible in some zooids. Peristome thick, most developed proximolaterally, producing a pair of prominent flaps. Adventitious avicularium placed laterally to the orifice, proximally or proximolaterally directed, polymorphic and variably sized, most often small and oval (about 55 μm long by 45 μm wide) or spatulate (about 100 μm long by 40 μm wide), rarely large and spatulate (285 μm long by 80 μm wide); crossbar complete. A triangular avicularium, about 60 μm long by 40 μm wide, with a raised rostrum, steeply inclined on the frontal plane and distolaterally directed inwardly, was observed placed on the proximal corner of two zooids. Ovicell represented by a single broken example lacking the roof, outline rounded, about 170 μm long by 220 μm wide. N, Number of colonies and number of zooids measured; SD, standard deviation. Remarks. A single colony fragment of Parasmittina agathae was found in our samples. This species at the present-day is known from Queensland and the Torres Strait at 12–36 m depth. It is characterized by the coarsely denticulate distal border, the prominent, lateral peristomial flaps, the relatively broad lyrula, the two distal oral spines, and the unique combination of adventitious avicularia variable in size and shape. Hayward & Parker (1994) also described for this species an erect, three-dimensional structure of hollow tubes developing from an encrusting base. Parasmittina dentigera Harmer, 1957 is similar to P. agathae in having an orifice with a denticulate distal border, but differs in having a peristome that is especially prominent proximally, and a distinct anvil-shaped lyrula.
- Published as part of Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, pp. 1-70 in Zootaxa 4419 (1) on pages 26-27, DOI: 10.11646/zootaxa.4419.1.1, http://zenodo.org/record/3769633