MARQUES ET AL.: AMPHIBIANS AND TERRESTRIAL REPTILES OF ANGOLA 
43 
noting that some species of these two groups were found in both areas and the turnover, instead of 
being abrupt was gradual, with southern taxa “diluting” towards the north, and some northern taxa 
extending considerably south. As an update to Bocage’s separation, Monard (1937b) proposed, 
however, that the border or turnover area would be a little bit north of the Kwanza (Table 4). He 
also recognized an Angolan endemic zone, roughly limited on the north by the Kwanza (Table 4). 
In the case of the amphibians, Monard (1938) provided a less detailed account, noting, however, 
that similar to the reptiles, the Angolan amphibians could be classified in four main groups — the 
“paraethiopian,” the “tropical,” the “austral,” and the endemic “Angolan” species (Table 4). Even 
though these groups exhibited an evident north-south turnover, similar to the reptiles, the bound¬ 
aries between them were not as clear as those for reptiles and appeared to be more related to 
drainage basins. 
Based on data on birds, especially those of western regions of the country. Hall (1960) high¬ 
lighted the biogeographic importance of the Escarpment in Angola. For him, the escarpment sepa¬ 
rated an "'Acacia Zone” in southwestern Angola and an extensive ''Brachystegia Zone” in the cen¬ 
tral area of the country. While the Brachystegia zone was mostly dominated by species “occurring 
in the woodlands of Central and East Africa,” those of the "'Acacia Zone” belong to “species found 
in South West Africa, except for a few, typical of the Escarpment Zone, which are found in fertile 
pockets on the edges of rivers north of Benguela, and in marshes and cultivation behind Benguela 
and Catumbela.” The “Escarpment Zone” divided Angolan birds in three main groups: those “with 
a representative form in the Escarpment Zone, and in either, or both, of the other zones,” those 
“with representative forms in the Brachystegia and Acacia Zones, partly isolated form each other 
by the Escarpment Zone”; and finally those “endemic, or nearly endemic, to the Escarpment Zone.” 
Hall (1960) argues that the Escarpment has worked as both a refligium and a barrier during past 
climate fluctuations, not only giving origin to Escarpment endemic forms, but also promoting 
separation of once single populations. The biogeographic importance of the Angolan Escarpment 
has been unanimously recognized by most authors concerned with Angola biogeography (e.g., 
Traylor 1963; Huntley 1974; Crawford-Cabral 1991; Huntley and Matos 1994; Dean 2000, 2001; 
Mills 2010; Clarck et al. 2011; Gon 9 alves and Goyder 2016), and new species of endemic mam¬ 
mals have been described from the area (Carleton et al. 2015; Svensson et al. 2017). 
Frade (1963) reviewed the available data on the biogeography of Angolan vertebrates, and 
proposed some modifications to both Bocage’s and Monard’s interpretations (Table 4). For reptiles 
he proposed the division of Angola into three main subregions, each one with specific “zones” — 
The “Western subregion,” comprising the north of the country and with a specific zone in “Cabin¬ 
da”; the “Plateaus subregion,” divided into the “Angolan plateau” and “Zambezian plateau” zones; 
and an “Arid subregion” without further divisions. For amphibians, the division was among two 
subregion and two zones, without any evident hierarchy between them — the “Western subregion 
and Angolan plateau zone,” mainly delimitated by the “Angolan or coastal hydrographic basins,” 
the “Congo basin zone,” the “Zambezian plateau zone,” and the “Arid subregion” (Table 4). 
Despite the zoogeographic importance attributed by Hall (1960) to the Escarpment, Frade did not 
extend Hall’s suggestions to other groups, including amphibians and reptiles. Frade (1963) was the 
last author to comment specifically upon and propose zoogeographic divisions to the Angolan 
herpetofauna. 
Following Frade’s revisionary work, few studies were dedicated to analyzing Angola 
zoogeography in a comprehensive way. One of greatest importance and comprehensiveness was 
that of Crawford-Cabral (1991), an unpublished document focused on a research plan for Angolan 
zoogeography, including a reproduction of an addendum to the author’s 1982 (also unpublished) 
PhD thesis, focused on the Zoogeography of Angolan mammals. Based on extensive data collec- 
