Hayward, B.W.; Holzmann, M.; Pawlowski, J.; Parker, J.H.; Kaushik, T.; Toyofuku, M.S.; Tsuchiya, M. (2021). Molecular and morphological taxonomy of living Ammonia and related taxa (Foraminifera) and their biogeography. Micropaleontology. 67: 109-313.
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Hayward, B.W.; Holzmann, M.; Pawlowski, J.; Parker, J.H.; Kaushik, T.; Toyofuku, M.S.; Tsuchiya, M.
2021
Molecular and morphological taxonomy of living Ammonia and related taxa (Foraminifera) and their biogeography
Micropaleontology
67: 109-313.
Publication
Available for editors
Globally, one of the two most common shallow-marine and estuarine foraminiferal genera is Ammonia. Over the past 50
years, the majority of workers have identified specimens in this genus as belonging to just 1–3 cosmopolitan species – A. beccarii, A.
tepida and A. parkinsoniana. This has been partly because of the problems of discriminating the Ammonia species based entirely on
shell morphology and partly because of a 1974 laboratory study that claimed to have shown that all morphologies were merely
ecophenotypic variants of one species – a conclusion that molecular studies have proven to be unequivocally wrong. In this study we
recognize, describe and figure sixty-seven living species and infraspecies of Recent Ammonia and two closely-related genera
(Acarotrochus, Pseudoeponides) from around the world and summarize their ecological and biogeographic distribution.
Twenty-six species and two subspecies are recognized by DNA sequencing and shown to be morphologically distinguishable. A
further 39 morphospecies and one subspecies, that have not yet been sequenced, have sufficiently distinct morphology to be recognized.
Canonical variates analysis using 42 measured or assessed morphological characters shows that the majority of these species can be
readily discriminated by their test morphologies, although a few of the less-ornamented molecular species are verging on being
pseudocryptic. Molecular sequencing of the type species of Challengerella (C. bradyi) and Helenina (H. anderseni) places them within
our Ammonia clade. Here we continue to recognize the morphologically highly distinct genera Pseudoeponides (subjective senior synonym
of Helenina) and allied Acarotrochus. Twenty new species or subspecies are described (molecular T types in brackets): Ammonia
abramovichae (T8), A. akitaae, A. aoteana australiensis (T5A), A. arabica (T26), A. ariakensis quiltyi, A. buzasi (T11), A. fajemilai, A.
goldsteinae, A. goodayi, A. haigi (T25), A. hattai, A. jorisseni (T23), A. justinparkeri, A. kitazatoi (T10), A. morleyae (T12), A.
shchedrinae, A. turgida almogilabinae (T22M), Acarotrochus lippsi, Pseudoeponides hottingeri and P. dubuissoni. Aneotype is designated
for A. veneta (Schultze 1854) (T1).We recognize 67 Ammonia and related taxa in this study but speculate that there may be 30 or
more additional living species that we are not yet confident to discriminate without molecular sequencing. Ammonia species live in most
parts of the world between 62 °N (Faeroe Islands) and 55 °S (Strait of Magellan), where seasonal sea-surface temperatures are 4–10° C
and above. One estuarine species (A. veneta, T1) is cosmopolitan, euryhaline and eurythermic. Several species are widespread in one or
two ocean regions (e.g., Atlantic and Mediterranean; South Pacific), whereas the majority are endemic to smaller areas (e.g., eastern
Mediterranean; Caribbean-Gulf of Mexico). Eleven biogeographic “provinces” are recognized by cluster analysis of presence/absence
records with the highest diversities in the Australian and northwest Pacific provinces with 18 and 19 species each). Levels of endemism
in our “provinces” range between 0 (temperate Atlantic) and 44% (Australian).
