colugos
After the flood

Colugo (Jean Baptiste Audebert, 1797)

The flying lemurs, or colugos, are a small group of Southeast Asian gliding mammals that make up the family Cynocephalidae within the order Dermoptera. There are two living genera, Cynocephalus (of the Philippines) and Galeopterus (from parts of Myanmar, Thailand, and Vietnam, through Malaysia into Indonesia). There has traditionally been a single described species of each genus, but genetic analysis suggests there are multiple species in each (Janecka et al. 2008; Mason et al. 2016). Colugos have a patagium, a skin membrane similar to those in flying squirrels and sugar gliders, used to glide between trees. The colugo’s patagium is more extensive than in other gliders, and is also used as a pouch to hold offspring when at rest. They are folivorous, primarily eating leaves, but occasionally fruit and small insects.

The fossil genus Dermotherium is the only other in the family. One species is known from Eocene Thailand (Ducrocq 1992), and another from Oligocene Thailand (Scott 2010). Additional fossil material from Eocene Myanmar and Oligocene Pakistan are also noted. While Dermotherium closely resembles living colugos (showing a ‘mosaic of characters found in both extant cynocephalid taxa’ [Scott 2010]), there are distinct differences also, and is probably not directly ancestral to the living genera.

Galeopterus in Thailand (CC BY-NC-SA 2.0 Petre Kimbely)

Several other families have been suggested as part of Dermoptera, but these are tenuous at best. (See the late Günter Bechly’s 2023 online review of the relationship switching, which often relates to attempts to determine closeness to primates.) From a creation biology perspective, it really doesn’t matter if, for example, the Mixodectidae or the Plagiomenidae are part of the order Dermoptera, or even if they are offshoots of the colugo baraminic lineage. Both of those families are known only from the Paleogene before they went extinct. Given how early they appear, and how different their teeth were from cynocephalids (Ducrocq 1992), however, it may be best to consider them separate baraminic lineages. In any case, the Cynocephalidae is certainly a monobaramin, where all known genera are part of the same baraminic lineage.

The secular evolutionary history suggests that, as both living and fossil colugos are endemic to Southeast Asia, their ‘deep evolutionary roots’ are likely in Asia, pending further paleontological evidence (Scott 2010). For creationists, we can best interpret the fossil history of colugos as a very early dispersion from the Ark in the Middle East, with rapid population growth towards Southeast Asia, and entrenchment there as the western population disappeared. That disappearance may have resulted from environmental changes occurring after the India-Eurasia continental collision, as rainforest regions turned arid. Limited diversification within colugos was likely due to the early successful capture of an arboreal niche—if it’s not broke, don’t fix it.