Vision in a Middle Ordovician trilobite eye

Gengo Tanaka, Brigitte Schoenemann, Khadija El Hariri, Teruo Ono, Euan Clarkson, Haruyoshi Maeda

研究成果: ジャーナルへの寄稿記事

3 引用 (Scopus)

抄録

Exceptionally well-preserved compound eyes of a Middle Ordovician trilobite, Cyclopyge sp., show remarkable detail, including each of the lenses and their distribution. Based on a new analysis using computed tomography and computer software, it has been established that the Cyclopyge sp. had an acute zone of enhanced visual acuity. The eye parameters (p) of the left eye of the specimen ranged from 0.02. μm. rad to 1.75. μm. rad (75th percentile. = 0.70. μm. rad) in the dorso-ventral direction and 0.26. μm. rad to 1.57. μm. rad (75th percentile. = 1.05. μm. rad) in the antero-posterior direction. These parameters indicated that the organism was adapted to strongly lit epipelagic conditions, which is comparable to adaptations exhibited by many present-day diurnal crustaceans. The results also suggest that this trilobite was not a diurnal migrant, because the eyes would have become inefficient under darker conditions. The lowest values of p were distributed in the ventral and posterior areas. This part of the eye was an acute zone with a wide field of view covering the lateral region, which indicated that the Cyclopyge sp. was probably not a predator. According to previous studies, early Middle Ordovician species inhabited the epipelagic as well as mesopelagic realms. From the viewpoint of the trilobite analysis, this study supports previous geological and palaeontological evidence that suggests that the epipelagic niche was invaded by at least the Middle Ordovician.

元の言語英語
ページ(範囲)129-139
ページ数11
ジャーナルPalaeogeography, Palaeoclimatology, Palaeoecology
433
DOI
出版物ステータス出版済み - 9 1 2015

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trilobite
Ordovician
eyes
compound eyes
Lens
computed tomography
field of view
niches
Crustacea
tomography
crustacean
niche
predators
predator
organisms
software
analysis
parameter

All Science Journal Classification (ASJC) codes

  • Oceanography
  • Ecology, Evolution, Behavior and Systematics
  • Earth-Surface Processes
  • Palaeontology

これを引用

Vision in a Middle Ordovician trilobite eye. / Tanaka, Gengo; Schoenemann, Brigitte; El Hariri, Khadija; Ono, Teruo; Clarkson, Euan; Maeda, Haruyoshi.

:: Palaeogeography, Palaeoclimatology, Palaeoecology, 巻 433, 01.09.2015, p. 129-139.

研究成果: ジャーナルへの寄稿記事

Tanaka, Gengo ; Schoenemann, Brigitte ; El Hariri, Khadija ; Ono, Teruo ; Clarkson, Euan ; Maeda, Haruyoshi. / Vision in a Middle Ordovician trilobite eye. :: Palaeogeography, Palaeoclimatology, Palaeoecology. 2015 ; 巻 433. pp. 129-139.
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