2.1 Eocene Mammals
The Eocene mammalian fauna is notable for its high proportion of extinct forms. Of the eight Orders represented, Cimolesta, Embrithopoda and Creodonta are extinct, as are all of the genera and species and most of the families. Many new species were recently described from the region (Pickford Reference Pickford2015a–Reference Pickford2015f, Reference Pickford2018a), thereby adding significantly to the known fauna of the epoch. Despite this, the diversity of taxa known from each Order is much lower than is the case with younger material. Whether this results from the paucity of sites (see below) remains to be seen. The Order Rodentia (rodents) is by far the most diverse, with eight families. Only Afrosoricida (tenrecs and golden moles) and Hyracoidea (hyraxes) have more than one, and, at three each, this is the most diverse at the family level they have been in the region. A fruit bat possibly belonging to the subfamily Propottininae has been described from Black Crow (Pickford Reference Pickford2018b) but not assigned to genus or species. It is significant in that it is the only member of the suborder Megachiroptera so far recovered from the region, although it cannot be included in the lists until a full identification has been published.
†Namalestes gheerbranti Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 468. Type locality: Black Crow. |
†Myohyrax Andrews, Reference Andrews1914. Quart. J. Geol. Soc. Lond. 70: 171. |
†Namatherium blackcrowense Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 479. Type locality: Black Crow. Additional references: Gheerbrandt et al. (Reference Gheerbrandt, Schmitt and Kocsis2018); Sanders et al. (Reference Sanders, Rasmussen, Kappelman, Werdelin and Sanders2010b). |
†Namahyrax corvus Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 474. Type locality: Black Crow. Comments: this taxon was originally assigned to Namahyracidae but is now placed in Geniohyidae by Pickford (Reference Pickford2018c). Additional references: Pickford (Reference Pickford2015e). |
†Notnamaia bogenfelsi Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 487. Type locality: Black Crow. Synonyms: Namaia. Additional references: Pickford and Uhen (Reference Pickford and Uhen2014). |
†Namaloris rupestris Pickford, Reference Pickford2015. Comm. Geol. Surv. Namibia 16: 196. Type locality: Eocliff. |
†Namaparamys inexpectatus Mein and Pickford, Reference Mein and Pickford2018. Comm. Geol. Surv. Namibia 18: 40, 41. Type locality: Black Crow. |
†Protophiomys algeriensis Jaeger, Denys and Coiffait, Reference Jaeger, Denys, Coiffait, Luckett and Hartenberger1985. In: Luckett and Hartenberger, Evolutionary Relationships Among Rodents: 569. Comments: these Protophiomys specimens may be Oligocene (Sallam and Seiffert Reference Sallam and Seiffert2016) or even Miocene in age (Marivaux et al. Reference Marivaux, Essid and Marzougui2014). |
†Glibia namibiensis Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 488. Type locality: Black Crow. Comments: this species is considered to belong to the genus Zegdoumys by Marivaux et al. (Reference Marivaux, Adaci and Bensalah2011, Reference Marivaux, Essid and Marzougui2015). | |
†Tsaukhaebmys calcareus Pickford, 2018. Comm. Geol. Surv. Namibia 18: 50, 51. Type locality: Black Crow. |
†Metaphiomys schaubi Wood, Reference Wood1968. Bull. Peabody Mus. Nat. Hist. 28: 58. | |
†Prepomonomys bogenfelsi Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 490. Type locality: Silica North. |
†Bathyergoides Stromer, Reference Stromer1923. Sitz. Math.-Physik. Klasse Bayer. Akad. Wiss. München 1923(II): 263. Type locality: Sperrgebiet. |
†Silicamys cingulatus Pickford, Senut, Morales, Mein and Sanchez, Reference Pickford, Senut, Morales, Mein and Sánchez2008. Geol. Surv. Namibia Mem. 20: 489. Type locality: Silica North. | |
†Talahphiomys lavocati Wood, Reference Wood1968. Bull. Peabody Mus. Nat. Hist. 20: 45. Synonyms: Phiomys. Additional references: Jaeger et al. (Reference Jaeger, Marivaux and Salem2010). |
†Apodecter stromeri Hopwood, Reference Hopwood1929. Amer. Mus. Novit. 344: 3. Type locality: Lüderitz Bay (south of) (?Langental: Mein and Pickford [Reference Mein and Pickford2008c]). | |
†Gaudeamus Wood, Reference Wood1968. Bull. Peabody Mus. Nat. Hist. 20: 68. | |
†Namaphiomys Mein and Pickford, unpublished. Comments: Namaphiomys is a nomen nudum, awaiting publication, according to M. Pickford (pers. comm. 2016). | |
†Phiomys phiomyoides Wood, Reference Wood1968. Bull. Peabody Mus. Nat. Hist. 20: 41. |
Comments: Pickford (Reference Pickford2018f) places this family within the Infraorder Hystricognathi (Suborder Ctenohystrica according to Huchon et al. [Reference Huchon, Catzeflis and Douzery2000, Reference Huchon, Madsen and Sibbald2002]) but Hystricognathi is included in the Suborder Hystricomorpha by Wilson and Reeder (Reference Wilson and Reeder2005), whose arrangement is followed here. | |
†Efeldomys Mein and Pickford 2008. Geol. Surv. Namibia Mem. 20: 257. Type locality: Elisabethfeld. Additional references: Pickford (Reference Pickford2018f). Comments: this genus was originally placed in Bathyergidae but is now transferred to Tufamyidae (Pickford, Reference Pickford2018f). | |
†Tufamys woodi Pickford, 2018. Comm. Geol. Surv. Namibia 19: 75. Type locality: Eocliff. |
†Pterodon De Blainville, Reference De Blainville1839. Ann. Franç. Etran. Anat. Physiol. 3: 23. Additional references: Holroyd (Reference Holroyd1999); Lewis and Morlo (Reference Lewis, Morlo, Werdelin and Sanders2010). |
†Bothriogenys gorringei Andrews and Beadnell, Reference Andrews and Beadnell1902. A preliminary note on some new mammals from the Upper Eocene of Egypt: 7. Additional references: Holroyd et al. (Reference Holroyd, Lihoreau, Gunnell, Miller, Werdelin and Sanders2010); Lihoreau and Ducrocq (Reference Lihoreau, Ducrocq, Prothero and Foss2007); Pickford (Reference Pickford2015f). |
2.2 Eocene Sites
Eocene sites (Figure 2.1) so far discovered in southern Africa have a very restricted distribution, all four of them being within the 2715-degree square. These earliest sites are also the most recent to have been discovered in the region.
Black Crow (2723:1528). Taxa: Diamantochloris inconcessus; Glibia namibiensis; Namahyrax corvus; Namalestes gheerbranti; Namaparamys inexpectatus; Namatherium blackcrowense; Notnamaia bogenfelsi; Pterodon; Tsaukhaebmys calcareus. References: Pickford (Reference Pickford2015a, Reference Pickford2018a–Reference Pickford2018d); Pickford et al. (Reference Pickford and Senut2008, Reference Pickford, Senut and Hipondoka2014).
Eocliff (2721:1536). Taxa: Arenagale calcareus; Efeldomys; Gaudeamus; Metaphiomys schaubi cf.; Myohyrax aff.; Namachloris arenatans; Namagale grandis; Namaloris rupestris; Namaphiomys; Phiomys lavocati aff.; Phiomys phiomyoides aff.; Prepomonomys bogenfelsi; Protophiomys algeriensis cf.; Silicamys cingulatus; Sperrgale minutus; Talahphiomys; Tufamys woodi. References: Pickford (Reference Pickford2015b, Reference Pickford2015c); Pickford et al. (Reference Pickford, Senut, Morales, Mein and Sánchez2008, Reference Pickford, Senut and Hipondoka2014).
Eoridge (2721:1537). Taxa: Bothriogenys gorringei; Rupestrohyrax palustris; Silicamys cingulatus; Sperrgale minutus. References: Pickford (Reference Pickford2015e, Reference Pickford2015f); Pickford et al. (Reference Pickford, Senut and Hipondoka2014).
Silica North and South (2715:1525; 2716:1525). Taxa: Apodecter stromeri cf.; Bathyergoides cf.; Prepomonomys bogenfelsi; Protophiomys algeriensis cf.; Silicamys cingulatus; Talahphiomys. References: Pickford et al. (Reference Pickford, Senut, Morales, Mein and Sánchez2008, Reference Pickford, Senut and Hipondoka2014).