Parasmittina agathae Hayward & Parker 1994

Autor: Martino, Emanuela Di, Taylor, Paul D.
Rok vydání: 2018
Předmět:
DOI: 10.5281/zenodo.3799555
Popis: 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 ��m long. Primary orifice broader than long, about 65 ��m long by 80 ��m 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 ��m long by 45 ��m wide) or spatulate (about 100 ��m long by 40 ��m wide), rarely large and spatulate (285 ��m long by 80 ��m wide); crossbar complete. A triangular avicularium, about 60 ��m long by 40 ��m 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 ��m long by 220 ��m 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
{"references":["Hayward, P. J. & Parker, S. A. (1994) Notes on some species of Parasmittina Osburn, 1952 (Bryozoa: Cheilostomatida). Zoological Journal of the Linnean Society, 110 (1), 53 - 75. https: // doi. org / 10.1111 / j. 1096 - 3642.1994. tb 01471. x","Kirkpatrick, R. (1890) Reports on the zoological collections made in Torres Straits by Professor A. C. Haddon, 1888 - 1889. Hydroida and Polyzoa. Scientific Proceedings of the Royal Dublin Society, New Series, 6, 603 - 626.","Harmer, S. F. (1957) The Polyzoa of the Siboga Expedition. Part 4. Cheilostomata Ascophora, II. Siboga Expedition Reports, 28 d, 641 - 1147."]}
Databáze: OpenAIRE
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