The fossil record and the origin of ticks revisited.

The fossil record of ticks has been classically used to discern the probable vicariance events of these arthropods, and to date the split moments of the different lineages. Although new techniques based on molecular clock methods are already available, tick fossil record still stands as a valuable source of information if correctly interpreted. Here we report about a male specimen of Ornithodoros (Alectorobius) sp. found in Dominican amber of about 25 millions years, illustrating its main morphological features. We also discuss the findings in a recent paper, which may contain unreliable interpretations on some fossil ticks. We support previous data on the presence of Argasidae in Miocene Dominican amber, and provide comments on the presence of ticks in Burmese amber. We further elaborate on the spread of ticks in the light of the record and description of a new family found in Cretaceous amber.