Canthon cotiae, Sanchez and Genise

Sánchez, M. V. & Genise, J. F., 2015, The Brood Ball ofCanthon (Canthon) LituratusGermar (Coleoptera: Scarabaeidae: Scarabaeinae) and Its Fossil CounterpartCoprinisphaera cotiaeSánchez and Genise New Ichnospecies, with a Brief Review of South American Fossil Brood Balls, The Coleopterists Bulletin 69 (1), pp. 73-82 : 73-82

Coprinisphaera cotiae Sánchez and Genise , new ichnospecies

( Fig. 4A )

Etymology. Dedicated to the first daughter Constantina , nicknamed Coti, of the first author.

Diagnosis. Coprinisphaera with an elongated protuberance at one pole with an internal conduit connecting the main chamber to the outside. The wall is of uniform thickness throughout the structure. There are no remains of a secondary chamber or additional structures. It is passively filled. which is open to the exterior by a rounded hole, 1 mm in diameter. Its wall is 2.7–5.0 mm thick. The external surface is slightly irregular, and the protuberance contains fragments of the rock matrix.

Occurrence. The holotype and only known specimen comes from the Puesto Almendra Member of the Middle Eocene–Lower Miocene Sarmiento Formation, Bajada del Diablo, Sierra de Talquino (Chubut province, Argentina). This Formation is a continental pyroclastic succession, 320 m thick, exposed in the center and north of Patagonia, Argentina ( Bellosi 2010). It has been extensively studied, particularly at Gran Barranca, the type locality of the Formation ( Madden et al. 2010). It is a classic locality for South American fossil mammals and also is rich in insect trace fossils including several Coprinisphaera ichnospecies ( Sánchez et al. 2010).

Comments. This ichnospecies differs from the other nine described to date ( Laza 2006; Krell and Schawaller 2011; Cantil et al. 2013; Sánchez et al. 2013) by the elongated protuberance that is internally crossed by a conduit that ends in a very tiny pore. On the outside, it resembles Coprinisphaera ndolanyana Krell, 2011, but in the latter the protuberance is shorter and truncated and lacks internal cavities (i.e., main chamber, conduit).

Holotype. One specimen (MACN-Icn 2169) collected by J. H. Laza, J. C. Quiroga, and F. Perez in 1984 and deposited in the Colección de Icnología of the Museo Argentino de Ciencias Naturales (Buenos Aires, Argentina).

Description. The holotype is 42 mm long and its main chamber, with a discrete wall of 3–5 mm thick, is 27 mm in equatorial diameter. The elongated protuberance is 15 mm long, 13 mm wide at its base, and 8 mm wide at the most distal part,

Figures

Fig. 4. Fossil brood balls Coprinisphaera cotiae, other South American Coprinisphaera ichnospecies, and Quirogaichnus coniunctus. A) Internal view of the sectioned holotype of C. cotiae (MACN-Icn 2169), B) Top view of the lectotype of C. murguiai (MLR 479b), C) Top-lateral view of a paratype of C. kraglievichi (MLR 319), D) Top view of the holotype of C. lazai (MACN-Icn 2058), E) External view (left) of the holotype of C. kheprii (MACN-Icn 1670) and internal view (right) of one half of a sectioned specimen (MACN-Icn 1417), F) External (left) and internal (right) views of the holotype of C. tonnii (MACN-Icn 1769), G) Internal view of the holotype of C. akatanka (MMP 4046), H) Top-lateral view of the holotype of C. kitu (EPN-Icn 003), I) Holotype of Q. coniunctus (MACN-Icn 2252). Scale bar = 1 cm.