Figure 36. Acropora tenella. A–C in Fossils reveal a high diversity of the staghorn coral genera Acropora and Isopora (Scleractinia: Acroporidae) in the Neogene of Indonesia

Figure 36. Acropora tenella. A–C, NHMUK PI AZ 7109, TF59, Bontang, East Kalimantan, Early to Middle Miocene (15.3– 17.9 Ma): A, fragment of a flattened branch, shown from its underside (left) and upperside (right), with radial corallites arranged in zig-zag pattern on the flanks; B and C, electron micrograph of the same branch. D and E, NHMUK PI AZ 7054, TF51, Stadion, Samarinda, East Kalimantan, Middle to Late Miocene (11.6 Ma): D, four fragments of a colony showing thicker basal branch (left corner) and thinner and flattened primary branches; E, AZ 7054a, electron micrograph of radial corallites and incipient axial on top. F, NHMUK PI AZ 7370, TF 57, Stadion, Samarinda, East Kalimantan, Middle to Late Miocene (11.6 Ma), branch with laterally arranged corallites. G–I, NHMUK PI AZ 8841, TF59, Bontang, East Kalimantan, Early to Middle Miocene (15.3–17.9 Ma): G, specimen showing sparse primary branches; H, electron micrograph of a primary branch with appressed tubular radial corallite with elaborated spinules relatively aligned; I, detail of coenosteum in between corallites formed of dense elaborate spinules.