357
indirect functional morphology indication) reported a supposed cirolaniid in premolting condition from the Cretaceous. Many cirolaniids have been reported from
the Miocene from South America and Japan, especially from the group of giant
isopods, Bathynomus (Kato et al. 2016; Maguire et al. 2018). Two ambiguous cases
of direct associations may question the scavenging lifestyle of cirolaniids
(Klompmaker and Boxshall 2015): These are (1) a single cirolaniid isopodan associated with a shark (Bowman 1971; Boucot and Poinar Jr 2010) and (2) an individual cirolaniid isopodan attached to the ventral side of a squid (Polz et al. 2006).
So far, no fossil representative of Corallanidae has been reported.
Only one fossil representative of Aegidae has been reported from the Late
Miocene (20 mya; indirect phylogenetic/functional morphology indication; Hansen
and Hansen 2010). The oldest fossil of representatives of Cymothoidae indicating
directly a parasitic lifestyle have been reported from the Jurassic (150 mya) from
the Solnhofen limestones (Fig. 10.2a; Nagler et al. 2016), although within the above
discussed phylogenetic framework it could also be possible that these forms are
offshoots of the lineage towards Cymothoidae + (Epicaridea + Urda + Gnathiidae)
or even of the lineage towards (Epicaridea + Urda + Gnathiidae). The oldest fossil
representatives of Cymothoida with a parasitic lifestyle (indicated indirectly by
functional morphology) have been reported from the Early Jurassic (168 mya) from
the group Urda (Nagler et al. 2017a). First body fossils of representatives of
Epicaridea (infective larva) have been reported from Cretaceous amber (100 mya)
from France (Néraudeau et al. 2017). An older and more indirect support for fossil
representatives of Epicaridea are pathological swellings in the branchial chamber of
decapods (Fig. 10.4; the swellings are usually referred to as Kanthyloma crusta) the
oldest swellings have been reported from the Early Jurassic (180 mya, though this
is a bit doubtful, see discussion in Klompmaker et al. 2014, the next oldest ones
would be Late Jurassic; Hessler 1969; Conway Morris 1990; Feldmann et al. 1993;
Wienberg Rasmussen et al. 2008; Klompmaker et al. 2014, 2016, 2021; Klompmaker
and Boxshall 2015; Robins and Klompmaker 2019). No fossil representative of
Gnathiidae has been reported yet.
10.4 Copepoda
10.4.1 General Aspects
Copepoda is a species-rich group of small and morphologically very diverse crustaceans, ubiquitous in all aquatic habitats, even occurring in some terrestrial habitats
(e.g., Reid 2001). Copepodans are extremely abundant, dominating the zooplankton
(Humes 1994). Yet, similar to isopodans, the current abundance of copepodans is
not reflected in the fossil record due to their small size and fragility (Selden et al.
2010), but they may have appeared already during the early Palaeozoic (Andres
1989, see below). Their lifestyle varies from planktic to benthic, with very different
10 Evolutionary History of Crustaceans as Parasites
indirect functional morphology indication) reported a supposed cirolaniid in premolting condition from the Cretaceous. Many cirolaniids have been reported from
the Miocene from South America and Japan, especially from the group of giant
isopods, Bathynomus (Kato et al. 2016; Maguire et al. 2018). Two ambiguous cases
of direct associations may question the scavenging lifestyle of cirolaniids
(Klompmaker and Boxshall 2015): These are (1) a single cirolaniid isopodan associated with a shark (Bowman 1971; Boucot and Poinar Jr 2010) and (2) an individual cirolaniid isopodan attached to the ventral side of a squid (Polz et al. 2006).
So far, no fossil representative of Corallanidae has been reported.
Only one fossil representative of Aegidae has been reported from the Late
Miocene (20 mya; indirect phylogenetic/functional morphology indication; Hansen
and Hansen 2010). The oldest fossil of representatives of Cymothoidae indicating
directly a parasitic lifestyle have been reported from the Jurassic (150 mya) from
the Solnhofen limestones (Fig. 10.2a; Nagler et al. 2016), although within the above
discussed phylogenetic framework it could also be possible that these forms are
offshoots of the lineage towards Cymothoidae + (Epicaridea + Urda + Gnathiidae)
or even of the lineage towards (Epicaridea + Urda + Gnathiidae). The oldest fossil
representatives of Cymothoida with a parasitic lifestyle (indicated indirectly by
functional morphology) have been reported from the Early Jurassic (168 mya) from
the group Urda (Nagler et al. 2017a). First body fossils of representatives of
Epicaridea (infective larva) have been reported from Cretaceous amber (100 mya)
from France (Néraudeau et al. 2017). An older and more indirect support for fossil
representatives of Epicaridea are pathological swellings in the branchial chamber of
decapods (Fig. 10.4; the swellings are usually referred to as Kanthyloma crusta) the
oldest swellings have been reported from the Early Jurassic (180 mya, though this
is a bit doubtful, see discussion in Klompmaker et al. 2014, the next oldest ones
would be Late Jurassic; Hessler 1969; Conway Morris 1990; Feldmann et al. 1993;
Wienberg Rasmussen et al. 2008; Klompmaker et al. 2014, 2016, 2021; Klompmaker
and Boxshall 2015; Robins and Klompmaker 2019). No fossil representative of
Gnathiidae has been reported yet.
10.4 Copepoda
10.4.1 General Aspects
Copepoda is a species-rich group of small and morphologically very diverse crustaceans, ubiquitous in all aquatic habitats, even occurring in some terrestrial habitats
(e.g., Reid 2001). Copepodans are extremely abundant, dominating the zooplankton
(Humes 1994). Yet, similar to isopodans, the current abundance of copepodans is
not reflected in the fossil record due to their small size and fragility (Selden et al.
2010), but they may have appeared already during the early Palaeozoic (Andres
1989, see below). Their lifestyle varies from planktic to benthic, with very different
10 Evolutionary History of Crustaceans as Parasites