Middle Permian (Roadian) gastropods from the Khao Khad Formation, Central Thailand: Implications for palaeogeography of the Indochina Terrane Author Ketwetsuriya, Chatchalerm Author Karapunar, Baran Author Charoentitirat, Thasinee Author Nützel, Al- Exander text Zootaxa 2020 2020-04-17 4766 1 1 47 journal article 10.11646/zootaxa.4766.1.1 ed4d1bf6-284a-4898-952a-58943d5a3026 1175-5334 3763907 urn:lsid:zoobank.org:pub:B1B5DA41-5035-4783-8D47-28857B6305AE Ampezzalina ? sp. ( Fig. 16 ) Material. One specimen: ESKU-19- LP 36. Dimensions (mm): ESKU-19- LP 36: height = 8.9; width = 11.7. Description. Shell trochiform, consisting of at least 2.5 whorl (apex missing); whorl face straight to slightly convex; whorl surface ornamented with at least seven spiral cords and equally spaced opisthocyrt fine collabral threads or strengthened growth lines; intersections between spiral cords and collabral threads forming a weak reticulate pattern with tiny nodes at intersections; six of the spiral cords equally strong; suprasutural spiral cord most prominent, representing shell periphery, with several coarse broken-off hollow spines; spines open in apertural direction, rounded convex in abapertural direction; base flatly convex, ornamented with spiral cords separated by concave interspace; the five strongest spiral cords situated at outer half of base; suture situated at outermost basal cord; basal cords evenly decreasing in prominence and more closely spaced toward umbilical area; minutely phaneromphalous; aperture not well-preserved but seemingly oblique. Remarks. The single present shell probably represents a new species, but due to the state of preservation we refrain from erecting a new species. This shell is unique in that it has a well-developed spiny cord just above abapical suture. Spine-forming cords are known from Mesozoic vetigastropods e.g., in the family Eucyclidae (e.g., Bandelastraea Nützel & Kaim, 2014 , Ampezzalina Bandel, 1993 ). Ampezzalina Bandel, 1993 and Bandelastraea Nützel & Kaim, 2014 might represent synonyms and their type species should be restudied. The single specimen has prominent suprasutural spines similar to type species of Ampezzalina ; therefore, placed in Ampezzalina instead of Bandelastraea . Ampezzalina is so far only known from the Triassic. It is possible that the abapical spiny spiral cord of the present specimen is a selenizone and in that case it would represent a new genus. However, the preservation is insufficient to be sure.