43
ceca of the tick, Cornupalpatum burmanicum (Ixodida: Ixodidae) in mid- Cretaceous
Myanmar amber (Poinar and Brown 2003) (Fig. 2.19) was infected with coccoid,
diplococcoid and short rod-shaped cells (Fig. 2.20). These rickettsial-like cells were
described as Palaeorickettsia protera. Their features closely resemble those of
extant rickettsia, which are known to occur in the body of extant ticks (Poinar
Fig. 2.19 An ixodid tick
larva, Cornupalpatum
burmanicum, in midCretaceous Myanmar
amber. Scale bar = 128 μm
Fig. 2.20 Short rods of
Palaeorickettsia protera in
the larva of
Cornupalpatum
burmanicum shown in
Fig. 2.19. Scale
bar = 2.0 μm
2 Fossil Record of Viruses, Parasitic Bacteria and Parasitic Protozoa