Porina australiensis ( Haswell, 1880 )

Martino, Emanuela Di & Taylor, Paul D., 2018, Early Pleistocene and Holocene bryozoans from Indonesia, Zootaxa 4419 (1), pp. 1-70 : 39-41

publication ID

https://doi.org/ 10.11646/zootaxa.4419.1.1

publication LSID

lsid:zoobank.org:pub:03CAFD21-185F-4C86-ACC3-8CEB61E7F7DD

DOI

https://doi.org/10.5281/zenodo.3799584

persistent identifier

https://treatment.plazi.org/id/CF6D87AA-E868-D266-FF7D-FD100F14FDA4

treatment provided by

Plazi

scientific name

Porina australiensis ( Haswell, 1880 )
status

 

Porina australiensis ( Haswell, 1880) View in CoL

( Figs 116–119 View FIGURES 116–119 ; Table 25)

Myriozoum australiense Haswell, 1880: 43 , pl. 3, figs 9–11.

Haswellia australiensis: Busk, 1884: 172 , pl. 24, fig. 9a.

Figured material. RGM.1350572, RGM.1350573, early Pleistocene, Java.

Description. Colony erect, rigid, new branches arising laterally at right angle. Branches cylindrical, subcircular in cross section, about 1 mm in diameter. Autozooids in whorls of six, arranged in alternating, longitudinal series; zooidal boundaries indistinct. Frontal shield flat, smooth, regularly and evenly perforated by small, circular to elliptical pseudopores, 20–30 µm long, arranged in longitudinal rows; ascopore distomedial, located at a short distance from the peristome, large, circular, 65–70 µm in diameter. Primary orifice semicircular with a small sinus, about 155 µm long (including sinus) by 170 µm wide; secondary orifice subcircular, about 140 µm long by 165 µm wide. Peristome projecting proximally, bearing two adjacent, small, elliptical avicularia on the proximal rim with no evidence of crossbar or condyles, probably broken. Frontal avicularia typically occur between longitudinal zooidal series, drop-shaped, with triangular, pointed rostrum, proximally directed, seemingly with two small, pointed pivotal condyles. Brooding zooids inflated distally.

Remarks. Ten fragments of Porina australiensis were found in our samples. Based on the examination of the type specimen of Spiroporina vertebralis ( Stoliczka, 1865) , and non-type specimens of Haswellia australiensis ( Haswell, 1880) , Gordon & d’Hondt (1997) recognized the two species as distinct but congeneric, both belonging to Porina . Harmer (1957, p. 846) reported Porina vertebralis from several stations off the Indonesian Archipelago and considered this species as a junior synonym of Porina australiensis . The two species differ in the position of the peristomial avicularia, located only on the projecting proximal rim in P. australiensis (and in our specimens), but also distally in P. vertebralis ( Gordon & d’Hondt 1997) . To confirm the conspecificity of our fossil specimens with P. australiensis , we examined non-type specimens of P. australiensis from the Challenger Expedition ( Figs 120–123 View FIGURES 120–123 ; NHMUK 87.12.9.700), identified and figured by Busk (1884, pl. 24, fig. 9a). The proximal peristomial rim of the Recent specimens appears more raised than that in the fossil material, and the avicularia clearly possess a complete pivotal bar, not observed in the fossil. However, these differences are likely due to preservation, as shown by the broken peristomes of the Recent specimens having exactly the same appearance as the fossils. It is more likely that Harmer’s specimens belong to the Recent P. australiensis than to the Miocene P. vertebralis , but these specimens need to be re-examined to affirm their conspecificity.

N, Number of colonies and number of zooids measured; SD, standard deviation; do, distance between midpoints of orifices of adjacent autozooids as an approximation of zooid size, following Berning (2007) and Rosso & Di Martino (2015); Per, peristomial, Av, avicularium.

RGM

National Museum of Natural History, Naturalis

Kingdom

Animalia

Phylum

Bryozoa

Class

Gymnolaemata

Order

Cheilostomatida

Family

Porinidae

Genus

Porina

Loc

Porina australiensis ( Haswell, 1880 )

Martino, Emanuela Di & Taylor, Paul D. 2018
2018
Loc

Haswellia australiensis:

Busk, G. 1884: 172
1884
Loc

Myriozoum australiense

Haswell, W. A. 1880: 43
1880
GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF