page_title: Ornithocercus
section_title: History of knowledge
hierarchical_section_title: Ornithocercus / History of knowledge
caption_attribution_description: English: From the original species description: Figure 4 from plate 23 of Stein, F.R. (1883) Der Organismus der Arthrodelen Flagellaten. II. Hälfte. 30 pp &amp; plates.
context_page_description: Ornithocercus is a genus of planktonic dinoflagellate that is known for its complex morphology that features considerable lists growing from its thecal plates, giving an attractive appearance. Discovered in 1883, this genus has a small number of species currently categorized but is widespread in tropical and sub-tropical oceans. The genus is marked by exosymbiotic bacteria gardens under its lists, the inter-organismal dynamics of which are a current field of research. As they reside only in warm water, the genus has been used as a proxy for climate change and has potential to be an indicator species for environmental change if found in novel environments.
context_section_description: “…Ornithocercus, [so] strange, even the most sober researcher will have [to give] some admiration … Ornithocercus magnificus, one of the most wonderful and strangest animal forms that ever happened to me” – Friedich Stein 1883 
  The genus Ornithocercus was first described in 1883 by German entomologist and zoologist Samuel Friedrich Nathaniel Ritter von Stein. He coined the genus with originally only one species: the holotype Ornithocercus magnificus.  He made his observations in the Atlantic Ocean and named the organism with regards to the wonder its form inspired in him.
  Stein originally grouped Ornithocercus in the Dinophysiden, a German taxonomic term that is no longer utilized. He specifically paired it with the genus Histioneis due to their morphological distinctiveness including what he described as a head-funnel and neck collar.
  Until DNA barcoding became accessible, specific demarcation in the genus was a significant challenge due to the variability in morphological traits (specifically the cingular lists). While beautiful figures were published in the early 20th century, often their scientific value was limited due to the incompleteness of morphological analyses. Although the most fundamental taxonomic feature was the thecal structure, relatively few papers were available before the 1970s that critically analyzed thecal plates. Several works reported the number of plates incorrectly. A review of previous publications and update with novel research published by Tohru Abe in 1967 indicated morphological features had been previously misinterpreted and given unwarranted significance taxonomically.
  Availability of enhanced microscope technology allowed greater morphological understanding. Scanning electron microscopes gave greater clarity to surface features as well as revealing the dissimilarity between inner and outer surfaces (such as pore openings) while transmission electron microscopes allowed insights into cell wall development. The study of morphological variability within Ornithocercus species is an ongoing field. A 2018 study found that species O. quadratus could be three separate morphospecies based on inferences from modern imaging techniques of morphology.
  The genus is not as diverse as other dinoflagellate genera such as Dinophysis but does have at least 24 recognized species. It has been extensively studied around the world, with species found to inhabit waters including the North Arabian Sea, Eastern Tropical Pacific, Indian Ocean, Red Sea, Vitiaz Strait, Caribbean Sea, Gulf of Aden, Southern Ocean, Boeton Str, California Current, Gulf of Mexico, Panamic Area, Peruvian Current Galapagos Eddy, and the coast of the Korean Peninsula.
caption: Ornithocercus Magnificus: From the original species description [6]
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