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, 16 (1), 203

Microtomography of the Baltic Amber Tick Ixodes Succineus Reveals Affinities With the Modern Asian Disease Vector Ixodes Ovatus


Microtomography of the Baltic Amber Tick Ixodes Succineus Reveals Affinities With the Modern Asian Disease Vector Ixodes Ovatus

Jason A Dunlop et al. BMC Evol Biol.


Background: Fossil ticks are extremely rare and Ixodes succineus Weidner, 1964 from Eocene (ca. 44-49 Ma) Baltic amber is one of the oldest examples of a living hard tick genus (Ixodida: Ixodidae). Previous work suggested it was most closely related to the modern and widespread European sheep tick Ixodes ricinus (Linneaus, 1758).

Results: Restudy using phase contrast synchrotron x-ray tomography yielded images of exceptional quality. These confirm the fossil's referral to Ixodes Latreille, 1795, but the characters resolved here suggest instead affinities with the Asian subgenus Partipalpiger Hoogstraal et al., 1973 and its single living (and medically significant) species Ixodes ovatus Neumann, 1899. We redescribe the amber fossil here as Ixodes (Partipalpiger) succineus.

Conclusions: Our data suggest that Ixodes ricinus is unlikely to be directly derived from Weidner's amber species, but instead reveals that the Partipalpiger lineage was originally more widely distributed across the northern hemisphere. The closeness of Ixodes (P.) succineus to a living vector of a wide range of pathogens offers the potential to correlate its spatial and temporal position (northern Europe, nearly 50 million years ago) with the estimated origination dates of various tick-borne diseases.

Keywords: Arachnida; Baltic amber; Eocene; Ixodida; Parasite; Parasitiformes; Vector.


Fig. 1
Fig. 1
Ixodes (Partipalpiger) succineus Weidner, 1964. A fossil tick in Eocene (44–49 Myr) Baltic amber; holotype and only known specimen GSUB I21. a Light microscopy image in dorsal view; note the cloudy precipitate occluding much of the dorsal surface. b The same in ventral view. Scale bar 1.0 mm
Fig. 2
Fig. 2
Tomographic renderings of Ixodes (P.) succineus. Numerous characters of taxonomic significance are now clearly revealed. a Oblique view. b Dorsal view. c Ventral view. d Details of gnathosoma. e Details of coxal region. Scale bar (for b and c) 1.0 mm
Fig. 3
Fig. 3
Interpretative drawing of Ixodes (P.) succineus in ventral view, highlighting taxonomically significant characters (see text for details). Scale bar 0.5 mm

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    1. Sonenshine D, Roe RM. (editors) Biology of Ticks, 2nd Edition. Bands 1–2. Oxford: Oxford Univ. Press; 2013.
    1. Guglielmone AA, Robbins RG, Apanaskevich DA, Petney TN, Estrada-Peña A, Horak IG, Shao R, Barker SC. The Argasidae, Ixodidae and Nutalliellidae (Acari: Ixodida) of the world: a list of valid species names. Zootaxa. 2010;2528:1–28.
    1. Klompen JSH, Black WC, IV, Keirans JE, Oliver JH., Jr Evolution of ticks. Annu Rev Entomol. 1996;41:141–61. - PubMed
    1. Baker SC, Murrell A. Phylogeny, evolution and historical zoogeography of ticks: a review of recent progress. Exp Appl Acarol. 2002;28:55–68. - PubMed
    1. De la Fuente J. The fossil record and the origin of ticks (Acari: Parasitiformes: Ixodida) Exp Appl Acarol. 2003;29:331–44. - PubMed

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