Cichla sp.

Carrillo-Briceño, Jorge D., Mora-Rojas, Laura, Hendricks, Kimberly, Vanegas, Andrés & Aguilera, Orangel, 2023, New clues on the palaeodiversity of the middle Miocene freshwater ichthyofauna from the Tatacoa Desert, Colombia, Geodiversitas 45 (10), pp. 327-351 : 334

cf. Cichla sp.

( Fig. 2 J1-J3).

MATERIAL EXAMINED. — Isolated dentary bone ( VPPLT-668B ) .

LOCALITY. — La Victoria Fm. Tatacoita (see Fig. 1 B; Appendix 1).

DESCRIPTION

VPPLT-668B is an incomplete dentary bone of 16 mm in length, missing the posterior part of the mandibular sensory canal and the coronoid process ( Fig. 2 J1-J2). The external face of the dentary preserves four well-developed foramina on the bony mandibular canal, the two smallest being located close to the dentary symphysis. All teeth are missing, and the preserved dorsal margin is characterized by six to seven circular tooth implantations rows of small size.

REMARKS

VPPLT-668B is easily distinguishable from VPPLT-668A assigned to cf. Astronotus . Our osteological comparisons suggest a close resemblance between VPPLT-668B and the dentaries of extant Cichla species ( Fig. 2 K1-K3) than with those of Crenicichla or other medium/large sizes South American cichlids. Although VPPLT-668B is incomplete, its dentary shape and the pattern and size of the tooth implantations rows resemble the jaw morphology of Cichla species. However, due to the state of preservation of VPPLT-668B and the absence of more specimens, for now, we prefer to refer to this fossil as cf. Cichla sp. The genus Cichla , contains the largest cichlid of South America, and is represented by at least 15 species from the Amazon and Orinoco basins, as well as rivers of the Guianas ( Froese & Pauly 2022). The extant species have a wide range of habitat preferences, including rivers and floodplain lakes ( van der Sleen & Albert 2018). The presence of cf. Cichla in the middle Miocene of the Honda Group represents the first fossil record for the genus.

From the Honda Group, Lundberg (1997) reported three premaxillaries, three dentaries, and two anguloarticular bones in fragmentary condition as indeterminate cichlids from the Fish Bed locality, suggesting a lack of morphological characters and relation to modern cichlids. Future work with more detailed anatomical comparisons on the specimens that Lundberg (1997) reported could support or contrast these assignments. Other new cichlid material reported herein includes an isolated anal spine (VPPLT-1164) coming from the Km 121 locality ( Appendix 1). The spine is 18 mm in length, robust and elongated, with a sharp end at the apical section, and typical of the anal region ( Fig. 2 L1-L2); nevertheless, taxonomic identification based on isolated spines is not possible.

Figures

FIG. 2. — Stingrays (A1-G2) and cichlids (H1-L2) from the Honda Group: A1, A2, cf. Potamotrygon sp. tooth (VPPLT 10000); B1-F, isolated dermal bucklers; B1, B2, VPPLT-1415; C, E, VPPLT-1245; D, VPPLT-1126; F, VPPLT-1239; G1, G2, isolated caudal spines (VPPLT-42) of Potamotrygonidae indet.; H1-H4, left dentary of cf. Astronotus sp. (VPPLT-668A); I1, I2, left dentary of the extant Astronotus ocellatus (Agassiz, 1831) (ANSP s/n); J1-J3, left dentary of cf. Cichla sp. (VPPLT-668B); K1-K3, left dentary of the extant Cichla Bloch & Schneider, 1801 (PIMUZ A/I 4897); L1, L2, indet. cichlid anal spine (VPPLT-1164). Views: L1, anterior; B, C-G1, H3, I2, J3, K3, dorsal; A1, labial; A2, lingual-lateral; H1, I1, J2, K1-K2, left lateral; L2, lateral; B2, profile; H4, J1, right lateral; G2, H2, ventral. Scale bars: A, 0.5 mm; B, 1 cm; C, E, I1, J, K2, 5 mm; D, H, 7 mm; F, K1, L, 6 mm; G, K3, 4 mm; I2, 3 mm.

FIG. 1. — Geographical position (A) of the Honda Group’s stratigraphic section (B) at La Venta site placed in the Upper Magdalena River Valley, Colombia. For details on the localities’ geographic coordinates and stratigraphic position, please see Appendix 2.