Inermorostrum xenops (lat.) Is a species of extinct mammals from the Xenorophidae family of the toothed whale suborder, the only one in the genus Inermorostrum . Fossil remains were found in the Oligocene sediments ( Rupelian age ) of the state of South Carolina ( USA ) [1] . One of the oldest types of toothless dolphins, characterized by dwarfism and, apparently, sucking their prey [2] [3] [4] .
| † Inermorostrum xenops |
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| Scientific classification |
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| No rank : | Bilateral symmetrical |
| Gender: | † Inermorostrum Boessenecker et al. 2017 |
| View: | † Inermorostrum xenops |
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| International scientific name |
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Inermorostrum xenops
Boessenecker et al. 2017 |
Geochronology
Rupelian Age33.9–28.1 Ma | million years | Era | F-d | Era |
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| | Th | TO
but
th
n
about
s
about
th | | 2,588 | | | 5.33 | Pliocene | N
e
about
g
e
n | | 23.03 | Miocene | | 33.9 | Oligocene | P
but
l
e
about
g
e
n | | 55.8 | Eocene | | 65.5 | Paleocene | | 251 | Mesozoic |
◄ Nowadays◄ Cretaceous-Paleogene extinction |
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Content
A dolphin skull was discovered at the bottom of the Wando River in Charleston, South Carolina . According to scientists, Inermorostrum xenops was 1.2 m long, which is significantly inferior to the size of modern dolphins (for example, bottlenose dolphins reach 4 m). The new species has a shortened snout, and, taking into account the structural features of the skull (in this species, the infraorbital foramen, through which the blood vessels and jaw nerves pass), may have thickened lips for sucking the victim, as well as vibrissae for quick detection of prey. This is associated with the proposed benthic diet, like walrus . Feed resources were soft-bodied invertebrates and small fish living on the seabed [2] [5] [6] .
The species Inermorostrum xenops was first described in 2017 by American paleontologists (Robert Busseneker, Daniel Fraser, Morgan Churchill and Jonathan Heisler) [2] and is included in the Xenorophidae family, first identified in 2008 (Uhen, 2008) [7] . The generic name Inermorostrum comes from the roots of lat. inermus - “without arms” or “defenseless” and rostrum - “nose”, “snout”, referring to the absence of teeth in the species, and the species name xenops is from Greek. xeno - “strange” and ops - “face”, due to the unusual morphology of this part of the body [2] .
- Leviathan Melville
- Cetacean evolution
- ↑ Inermorostrum xenops (English) information on the Paleobiology Database website. (Retrieved April 24, 2018) .
- ↑ 1 2 3 4 Robert W. Boessenecker, Danielle Fraser, Morgan Churchill, Jonathan H. Geisler. A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti) (English) // Proceedings of the Royal Society B: Biological Sciences: Journal. - L .: Royal Society, 2017 .-- Vol. 284, no. 1861 . - P. 1-8. - DOI : 10.1098 / rspb.2017.05.05 .
- ↑ A dolphin sucking to death was found (neopr.) . Lenta.ru (August 24, 2017). Date of treatment August 25, 2017.
- ↑ Scientists have discovered a new species of ancient dolphins. They sucked fish and squid with a toothless mouth (neopr.) . Meduza (August 23, 2017). Date of treatment August 25, 2017.
- ↑ Heather Brady. New Species of Prehistoric Dolphin Slurped Up Its Prey . nationalgeographic.com August 23, 2017.
- ↑ Ekaterina Rusakova. Toothless dolphins that lived 29 million years ago turned out to be "suckers . " nplus1.ru August 24, 2017.
- ↑ Uhen MD 2008. A new Xenorophus-like odontocete cetacean form the Oligocene of North Carolina and a discussion of the basal odontocete radiation. Journal of Systematic Paleontology 6 (4): 433–452.
- Marx FG, Lambert O., Uhen MD Cetacean paleobiology. - Oxford, UK: Wiley Blackwell, 2016.
- Geisler JH, Boessenecker RW, Brown M., Beatty BL The Origin of Filter Feeding in Whales // Current Biology: Journal. - 2017 .-- Vol. 27, no. 13 . - P. 2036-2042.e2. - DOI : 10.1016 / j.cub.2017.06.06.003 .
