Figure 27 in Fossils reveal a high diversity of the staghorn coral genera Acropora and Isopora (Scleractinia: Acroporidae) in the Neogene of Indonesia

Figure 27. Acropora tortuosa. NHM UK Pl AZ 8847, TF504, Bontang, East Kalimantan, Late Miocene (9.4–9.8 Ma). A, two straight branches interpreted as middle part of a colony. B and C, AZ 8847a: B, detail showing secondary branch; C, electron micrograph showing incipient axial and radial corallites with costate walls, triangle indicates a small radial. D–F, AZ 8847b: D, rounded tubular and subimmersed corallites at the base of a branch; E, transverse section showing axial corallite; F, detail of coenosteum formed of slightly elaborated spinules.