Praomys lukolelae Hatt 1934

Praomys lukolelae Hatt 1934, Am. Mus . Novit., 708: 13.

Type Locality: Dem. Rep. Congo, Equateur, Lukolela.

Vernacular Names: Lukolela Praomys.

Distribution: N Dem. Rep. Congo; recorded from the type locality and Kisangani region in Orientale (specimens in UCA).

Conservation: IUCN – Near Threatened as Malacomys lukolelae .

Discussion: F. Petter (1975 c) and Chevret et al. (1994) recorded P. lukolelae from the Central African Republic, but the specimens we have seen from that series represent an undescribed species of Praomys in the P. tullbergi group (see also Lecompte et al., 2001, 2002 a, b) that has now been described as P. petteri (see that account). Up to 1990, P. lukolelae was represented only by the three specimens in the type series (Van der Straeten and Dudu, 1990), but we have examined 90 specimens from the Kisangani region that are morphologically closely similar to the three examples from Lukolela. Hatt (1934 b) described lukolelae as a subspecies of Praomys tullbergi, but its long and very slim hind feet, tip of short fifth digit extending only to base of digital pad of fourth digit, very large ears, cranial conformation, and molar dental patterns identify the specimens as a separate species. Citing those same traits, Musser and Carleton (1993) placed lukolelae in Malacomys, noting its close morphological similarity with verschureni, which had been described as a species of Malacomys and was still associated with that genus in the early 1990s. Compared with Praomys, the species of Malacomys tend to have a small or no subsquamosal fenestra (usually large in Praomys), no cusp t3 on second upper molar (usually present), no anterolabial or posterolabial cusplets on first and second lower molars (present in most specimens), and the three central digits of the hind foot very long relative to the two outer digits (shorter in Praomys). In addition to the external traits mentioned above, the type series of lukolelae and specimens from Kisangani exhibit subsquamosal variation similar to that in Malacomys, most specimens lack a cusp t3 on the second upper molar, most do not have anterolabial and posterolabial cusplets on the lower molars, and configuration of the digits is like that in Malacomys .

Van der Straeten and Dudu (1990) had recognized a Praomys lukolelae group containing only that species and stated that Malacomys verschureni was related to the P. lukolelae complex. By 1999, Van der Straeten and Kerbis Peterhans (1999:89) recognized a " lukolelae species-complex enclosing lukolelae and probably verschureni (described as Malacomys)." Van der Straeten’s view received support from Denys, who was studying the lukolelae complex and wrote in 1995 (in litt.) that her study of cranial and dental traits would align lukolelae with Praomys rather than Malacomys . We defer to our colleagues’ allocations and list both species in Praomys but stress the need for critical phylogenetic study of lukolelae and verschureni in relation to the species of Malacomys and Praomys and reevaluation of generic boundaries. In our study of this group we appreciated the distinctions between species of Praomys and Malacomys but also detected close morphological alliance between them, in particular the P. tullbergi complex and Malacomys, with P. lukolelae and P. verschureni nearly bridging the gap in several diagnostic characters. This assessment, however, clashes with cladistic analyses of morphological traits (Lecompte et al., 2002 a), sequences from complete mtDNA cytochrome b (Lecompte et al., 2002 b) and nuclear IRBP gene sequences (E. Lecompte, in litt., 2002), which do not cluster Malacomys even close to any genus in Stenocephalemys Division or any subgroup of Praomys .

In the morphometric analysis of type specimens of Praomys, Mastomys, Myomys (Myomyscus), and Hylomyscus by Van der Straeten and Robbins (1997), the holotype of lukolelae clustered with holotypes of taxa associated with Praomys, which to them endorsed the association of lukolelae with Praomys and not Malacomys . But this connection is unwarranted without comparison with holotypes representing species of Malacomys, taxa omitted from their analysis.