Whale barnacles and Neogene cetacean migration routes

Biotically constrained palaeoenvironmental conditions of a mid-Holocene intertidal lagoon on the southern shore of the Arabian Gulf: evidence associated with a whale skeleton at Musaffah, Abu Dhabi, UAE

“…It would be interesting to know the relationship between C. diadema barnacles with the humpback population represented by the remains at Musaffah. This is because the life cycle of these barnacles is thought to relate to the migration routes of humpback whales (Bianucci et al, 2006a) and the nearest modern humpback population (in the Arabian Sea) is claimed to be relatively sedentary (Mikhalev, 1997). This may suggest that the Arabian Sea humpback whales are less sedentary than suggested by Mikhalev (1997) or that the C. diadema barnacles associated with the Arabian Sea humpback whales may represent an isolated population with respect to conspecifics.…”

“…These barnacles were identified as the sessile barnacle Coronula diadema due to their crown-shape with convex ribs (Darwin, 1854;Pilsbury, 1916), distinguishing them from Coronula reginae with a more globulo-conical or depressed shape and more flattened, longitudinal ribs. There are fossil taxa in the genus Coronula such as Coronula barbara and Coronula bifida, dating from the Pliocene of the Mediterranean and British Isles (Bianucci et al, 2006a), although it is doubtful that these are relevant in this instance. Both C. diadema and C. reginae are species associated with cetaceans.…”

Late Pleistocene gray whales (Eschrichtius robustus) offshore Georgia, U.S.A., and the antiquity of gray whale migration in the North Atlantic Ocean

“…Thus far, this taxon has no fossil record, but remains of this barnacle might be recovered from JY Reef with further investigation. Interestingly, Pleistocene fossils of another barnacle parasite, Coronula diadema, which is preferentially hosted (but not uniquely) by humpback whales (Megaptera novaeangliae), have been used to trace ancient migratory routes along South America and in the Mediterranean Sea (Bianucci et al, 2006). The inference that Coronula detaches from their hosts along migratory routes or in breeding areas (Bianucci et al, 2006) holds promise for finding such proxies at JY Reef and other localities.…”

Fossil whale barnacles from the lower Pleistocene of Sicily shed light on the coeval Mediterranean cetacean fauna

“…Although all the fossil occurrences of whale barnacles published so far are reasonably referable to the Pliocene or Quaternary (COLLARETA et al, 2016a, and previous references therein), some unpublished coronulid specimens from Taiwan may be older (i.e., late Miocene; John BUCKERIDGE, personal communication, 2018). Based on the remarkable host preferences of extant whale barnacle species, and considering that the detachment of coronulid shells from their host's skin has been observed along migration routes and especially in cetacean breeding/calving grounds (BIA- NUCCI et al, 2006b, and references therein), the fossil remains of whale barnacles have recently been interpreted as markers of ancient mysticete distributional and migration patterns (BIANUCCI et al, 2006a(BIANUCCI et al, , 2006bÁLVAREZ-FERNÁNDEZ et al, 2014;BOSSELAERS & COLLARETA, 2016;COLLARETA et al, 2016bCOLLARETA et al, , 2017BOSSELAERS et al, 2017). From this perspective, whale barnacle remains cease to be exclusively regarded as body fossils, assuming instead an additional role -i.e., providing indirect evidence for the passage of their cetacean hosts -that makes them conceptually similar to trace fossils.…”

“…Based on this record, mainly consisting of upper Pliocene to mid-lower Pleistocene occurrences of the extinct species Coronula bifida BRONN, 1831, and few upper lower Pleistocene (Calabrian) occurrences of the extant species Coronula diadema, BIANUCCI et al (2006aBIANUCCI et al ( , 2006b proposed that, unlike today, balaenopteroid whales may have used the Mediterranean as a breeding ground during the latest Neogene and part of the Quaternary.…”