Was the Devonian placoderm Titanichthys a suspension feeder?
Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an in...
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| Format: | Article |
| Language: | English |
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The Royal Society
2020-05-01
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| Series: | Royal Society Open Science |
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| Online Access: | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.200272 |
| _version_ | 1819063114010722304 |
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| author | Samuel J. Coatham Jakob Vinther Emily J. Rayfield Christian Klug |
| author_facet | Samuel J. Coatham Jakob Vinther Emily J. Rayfield Christian Klug |
| author_sort | Samuel J. Coatham |
| collection | DOAJ |
| description | Large nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an inherent relationship with ocean primary productivity and how past and future perturbations to these may impact on the different tiers of the food web. The evolution of large nektonic suspension feeders—‘gentle giants’—occurred four times among chondrichthyan fishes (e.g. whale sharks, basking sharks and manta rays), as well as in baleen whales (mysticetes), the Mesozoic pachycormid fishes and at least twice in radiodontan stem group arthropods (Anomalocaridids) during the Cambrian explosion. The Late Devonian placoderm Titanichthys has tentatively been considered to have been a megaplanktivore, primarily due to its gigantic size and narrow, edentulous jaws while no suspension-feeding apparatus have ever been reported. Here, the potential for microphagy and other feeding behaviours in Titanichthys is assessed via a comparative study of jaw mechanics in Titanichthys and other placoderms with presumably differing feeding habits (macrophagy and durophagy). Finite-element models of the lower jaws of Titanichthys termieri in comparison to Dunkleosteus terrelli and Tafilalichthys lavocati reveal considerably less resistance to von Mises stress in this taxon. Comparisons with a selection of large-bodied extant taxa of similar ecological diversity reveal similar disparities in jaw stress resistance. Our results, therefore, conform to the hypothesis that Titanichthys was a suspension feeder with jaws ill-suited for biting and crushing but well suited for gaping ram feeding. |
| first_indexed | 2024-12-21T15:09:31Z |
| format | Article |
| id | doaj.art-08e1ba2358ad48a79523c521366591ea |
| institution | Directory Open Access Journal |
| issn | 2054-5703 |
| language | English |
| last_indexed | 2024-12-21T15:09:31Z |
| publishDate | 2020-05-01 |
| publisher | The Royal Society |
| record_format | Article |
| series | Royal Society Open Science |
| spelling | doaj.art-08e1ba2358ad48a79523c521366591ea2022-12-21T18:59:19ZengThe Royal SocietyRoyal Society Open Science2054-57032020-05-017510.1098/rsos.200272200272Was the Devonian placoderm Titanichthys a suspension feeder?Samuel J. CoathamJakob VintherEmily J. RayfieldChristian KlugLarge nektonic suspension feeders have evolved multiple times. The apparent trend among apex predators for some evolving into feeding on small zooplankton is of interest for understanding the associated shifts in anatomy and behaviour, while the spatial and temporal distribution gives clues to an inherent relationship with ocean primary productivity and how past and future perturbations to these may impact on the different tiers of the food web. The evolution of large nektonic suspension feeders—‘gentle giants’—occurred four times among chondrichthyan fishes (e.g. whale sharks, basking sharks and manta rays), as well as in baleen whales (mysticetes), the Mesozoic pachycormid fishes and at least twice in radiodontan stem group arthropods (Anomalocaridids) during the Cambrian explosion. The Late Devonian placoderm Titanichthys has tentatively been considered to have been a megaplanktivore, primarily due to its gigantic size and narrow, edentulous jaws while no suspension-feeding apparatus have ever been reported. Here, the potential for microphagy and other feeding behaviours in Titanichthys is assessed via a comparative study of jaw mechanics in Titanichthys and other placoderms with presumably differing feeding habits (macrophagy and durophagy). Finite-element models of the lower jaws of Titanichthys termieri in comparison to Dunkleosteus terrelli and Tafilalichthys lavocati reveal considerably less resistance to von Mises stress in this taxon. Comparisons with a selection of large-bodied extant taxa of similar ecological diversity reveal similar disparities in jaw stress resistance. Our results, therefore, conform to the hypothesis that Titanichthys was a suspension feeder with jaws ill-suited for biting and crushing but well suited for gaping ram feeding.https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.200272suspension feedingtitanichthysarthrodiradevoniancomparative biomechanics |
| spellingShingle | Samuel J. Coatham Jakob Vinther Emily J. Rayfield Christian Klug Was the Devonian placoderm Titanichthys a suspension feeder? Royal Society Open Science suspension feeding titanichthys arthrodira devonian comparative biomechanics |
| title | Was the Devonian placoderm Titanichthys a suspension feeder? |
| title_full | Was the Devonian placoderm Titanichthys a suspension feeder? |
| title_fullStr | Was the Devonian placoderm Titanichthys a suspension feeder? |
| title_full_unstemmed | Was the Devonian placoderm Titanichthys a suspension feeder? |
| title_short | Was the Devonian placoderm Titanichthys a suspension feeder? |
| title_sort | was the devonian placoderm titanichthys a suspension feeder |
| topic | suspension feeding titanichthys arthrodira devonian comparative biomechanics |
| url | https://royalsocietypublishing.org/doi/pdf/10.1098/rsos.200272 |
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