vi
reveal patterns of co-evolution and host switching. Fossils, however, are essential to
calibrate clocks even though this is challenging due to the rare occurrence of parasites in the fossil record. Fossils may also provide more direct evidence of ancient
parasite–host relationships. In rare cases they preserve associations that no longer
persist, showing that initial hosts were different from those that are favoured today.
The remarkable 430 million-year-old Silurian Herefordshire deposit in England, for
example, which I have been investigating with colleagues for the last 25 years, has
yielded a pentastomid crustacean which is clearly ectoparasitic on marine ostracods
(examples are preserved attached to the ostracod carapace, and on eggs within it).
Living pentastomids, in contrast, apart from a few exceptions that live on insects,
are parasitic on terrestrial vertebrates where they invade the respiratory system.
A surprising range of parasites are represented in the fossil record but they have
received relatively little attention to date, at least in terms of a major synthesis, an
omission that is remedied here in grand style. The importance of parasitism is
reflected in 25 contributions by more than 50 authors. All the important groups of
parasites are reviewed: bacteria, protozoa, fungi, cnidarians, bivalves, gastropods,
helminths, acanthocephalans, chelicerates, crustaceans and insects as well as fossil
evidence on their impact on hosts: colonial organisms, crustaceans, trilobites, cephalopods, bivalves, echinoderms, vertebrates. The major issues covered include the
ways in which parasites and their effects are fossilised, the evolution of host–parasite associations, the history of parasitism as recorded in the fossil record, and the
utility of genomics and the molecular clock in revealing the course of host–parasite
evolution. This welcome compilation will provide an indispensable platform for
future work on this fascinating topic.
Yale University
Derek E. G. Briggs
New Haven, CT, USA
Foreword
reveal patterns of co-evolution and host switching. Fossils, however, are essential to
calibrate clocks even though this is challenging due to the rare occurrence of parasites in the fossil record. Fossils may also provide more direct evidence of ancient
parasite–host relationships. In rare cases they preserve associations that no longer
persist, showing that initial hosts were different from those that are favoured today.
The remarkable 430 million-year-old Silurian Herefordshire deposit in England, for
example, which I have been investigating with colleagues for the last 25 years, has
yielded a pentastomid crustacean which is clearly ectoparasitic on marine ostracods
(examples are preserved attached to the ostracod carapace, and on eggs within it).
Living pentastomids, in contrast, apart from a few exceptions that live on insects,
are parasitic on terrestrial vertebrates where they invade the respiratory system.
A surprising range of parasites are represented in the fossil record but they have
received relatively little attention to date, at least in terms of a major synthesis, an
omission that is remedied here in grand style. The importance of parasitism is
reflected in 25 contributions by more than 50 authors. All the important groups of
parasites are reviewed: bacteria, protozoa, fungi, cnidarians, bivalves, gastropods,
helminths, acanthocephalans, chelicerates, crustaceans and insects as well as fossil
evidence on their impact on hosts: colonial organisms, crustaceans, trilobites, cephalopods, bivalves, echinoderms, vertebrates. The major issues covered include the
ways in which parasites and their effects are fossilised, the evolution of host–parasite associations, the history of parasitism as recorded in the fossil record, and the
utility of genomics and the molecular clock in revealing the course of host–parasite
evolution. This welcome compilation will provide an indispensable platform for
future work on this fascinating topic.
Yale University
Derek E. G. Briggs
New Haven, CT, USA
Foreword