Thalamoporella sp. 1

Thalamoporella sp. 1

Figure 1 View FIGURE 1

Figured material. PMC EDM-Collection J.H.B.119a, sample 19206 ( Figure 1A–B View FIGURE 1 ) and sample 19084 ( Figure 1C–E View FIGURE 1 ); Core 19, Daidokutsu cave, Okinawa, Japan, Holocene.

Sample Depth Age Bryozoa ID (cm) (Y) (P or A)

19001 0 0 P

19002 1 P

19003 2 P

19004 3 183 P

19005 4 229 P

19006 5 P

19007 6 P

19008 7 P

19009 8 400 P

19010 9 P

19011 10 P

19012 11 P

19013 12 557 P

19014 13 P

19015 14 P

19016 15 P

19017 16 P

19018 17 743 P

19019 18 779 P

19020 19 P

19021 20 P

19022 21 P

19023 22 P

19024 23 P

19025 24 P

19026 25 P

19027 26 1067 P

19028 27 P

19029 28 1139 P

19030 29 P

19031 30 1211 P

19032 31 P

19033 32 P

19034 33 1321 P

19035 34 P

19036 35 P

19037 36 P

19038 37 1470 P

19039 38 1508 P

19040 39 P

19041 40 P

Sample Depth Age Bryozoa ID (cm) (Y) (P or A)

19042 41 P

19043 42 P

19044 43 P

19045 44 P

19046 45 P

19047 46 P

19048 47 P

19049 48 P

19050 49 1942 P

19051 50 P

19052 51 P

19053 52 P

19054 53 A

19055 54 2152 P

19056 55 P

19057 56 P

19058 57 P

19059 58 P

19060 59 A

19061 60 2415 P

19062 61 P

19063 62 P

19064 63 P

19065 64 2594 P

19066 65 P

19067 66 P

19068 67 P

19069 68 P

19070 69 2819 A

19071 70 P

19072 71 P

19073 72 A

19074 73 P

19075 74 P

19076 75 P

19077 76 P

19078 77 P

19079 78 3213 A

19080 79 P

19081 80 P

19082 81 P

TABLE 1 (continued).

Sample Depth Age Bryozoa ID (cm) (Y) (P or A)

19083 82 P

19084 83 P

19085 84 3458 P

19086 85 3497 A

19087 86 P

19088 87 P

19089 88 P

19090 89 A

19091 90 3686 P

19092 91 P

19093 92 P

19094 93 P

19095 94 P

19104 103 4120 P

19105 104 4151 P

19109 108 P

19112 111 4354 P

19113 112 4382 P

19114 113 4409 P

19115 114 4436 P

19119 118 4542 P

19120 119 4567 P

19121 120 P

19122 121 4618 A

19125 124 P

19127 126 P

19128 127 4765 A

19129 128 4788 A

19132 131 P

19133 132 4882 A

19134 133 4904 A

19135 134 P

19136 135 4950 A

19140 139 P

19143 142 P

19144 143 5125 A

19147 146 5188 P

19148 147 5209 A

19150 149 P

19151 150 5250 A

19152 151 5292 P

Description. Colony encrusting, multiserial, unilaminar. Autozooids distinct, outlined by a thin rim of smooth gymnocyst, rectangular to hexagonal, elongate (mean ZL/ZW 1.49). Cryptocyst extensive, consisting of a raised, wide (27–64 µm), ropelike rim along proximal and lateral zooidal margins, convex, sloping towards the centre of zooid frontal surface between opesia and opesiules, slightly depressed and flat below opesiules, coarsely granular (granule diameter 14–29 µm), with a few, sparse pseudopores concentrated mainly in the proximal portion (pseudopore diameter 5–10 µm); pierced by two symmetrical, elliptical opesiules placed in the distal third of the zooid, just below the proximal margin of opesia. Gymnocyst reduced, visible distally and laterally to the opesia, usually more extensive laterally, reaching width of 43–76 µm; in a single zooid a preserved adoral tubercle of c. 33 µm in diameter. Opesia eye-shaped, occupying the distal third of zooidal length (mean OpL/ZL 0.30). A single heterozooid observed, lozenge-shaped, shorter than autozooid, symmetrical; cryptocyst coarsely granular, imperforate, lacking condyles or pivotal bar; distal margin triangular, opesia oval; sibling zooids not torqued towards heterozooid. Ovicells not seen.

Measurements (µm). ZL 569±43, 514–653 (2, 12); ZW 381±48, 272–449 (2, 12); OpL 172±12, 149– 187 (2, 12); OpW 203±16, 166–224 (2, 12); OpesL 75±12, 56–92 (2, 12); OpesW 54±5, 47–62 (2, 12); AvL 453 (1, 1); AvW 262 (1, 1); AvOpL 207 (1, 1); AvOpW 147 (1, 1).

Remarks. Typically, vicarious avicularia in Thalamoporella have a prominently elevated rostrum with smooth lateral ‘wings’, and robust condyles or a complete crossbar. These characteristics, however, are absent in the single heterozooid observed, raising the possibility that it might be a

PALAEO- ELECTRONICA.ORG kenozooid. Kenozooids, which are polymorphs that often form to fill geometric gaps within the colony, are common in species of Thalamoporella . Examples include the middle Miocene T. polygonalis Di Martino, Taylor and Portell, 2017 from Florida, and the Recent T. lanceolata Soule, Soule and Chaney, 1999 from Fiji and Samoa. The Recent Thalamoporella stapifera Levinsen, 1909 from Indonesia bears the closest resemblance in overall appearance and autozooid size range to the Okinawan species. However, the absence of more detailed features, such as the clear presence of vicarious avicularia, prevents further comparison and identification at the species level.