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Kiel S, Goedert JL, Huynh TL, Krings M, Parkinson D, Romero R, Looy CV. Early Oligocene kelp holdfasts and stepwise evolution of the kelp ecosystem in the North Pacific. Proc Natl Acad Sci U S A 2024; 121:e2317054121. [PMID: 38227671 PMCID: PMC10823212 DOI: 10.1073/pnas.2317054121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/27/2023] [Indexed: 01/18/2024] Open
Abstract
Kelp forests are highly productive and economically important ecosystems worldwide, especially in the North Pacific Ocean. However, current hypotheses for their evolutionary origins are reliant on a scant fossil record. Here, we report fossil hapteral kelp holdfasts from western Washington State, USA, indicating that kelp has existed in the northeastern Pacific Ocean since the earliest Oligocene. This is consistent with the proposed North Pacific origin of kelp associated with global cooling around the Eocene-Oligocene transition. These fossils also support the hypotheses that a hapteral holdfast, rather than a discoid holdfast, is the ancestral state in complex kelps and suggest that early kelps likely had a flexible rather than a stiff stipe. Early kelps were possibly grazed upon by mammals like desmostylians, but fossil evidence of the complex ecological interactions known from extant kelp forests is lacking. The fossil record further indicates that the present-day, multi-story kelp forest had developed at latest after the mid-Miocene climate optimum. In summary, the fossils signify a stepwise evolution of the kelp ecosystem in the North Pacific, likely enabled by changes in the ocean-climate system.
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Affiliation(s)
- Steffen Kiel
- Department of Palaeobiology, Swedish Museum of Natural History, Stockholm10405, Sweden
| | - James L. Goedert
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA98195
| | - Tony L. Huynh
- School of Medicine, University of California, San Francisco, CA94143
| | - Michael Krings
- Staatliche Naturwissenschaftliche Sammlungen Bayerns-Bayerische Staatssammlung für Paläontologie und Geologie, Munich80333, Germany
- Department für Geo- und Umweltwissenschaften, Paläontologie und Geobiologie, Ludwig-Maximilians-Universität, Munich80333, Germany
| | - Dula Parkinson
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Rosemary Romero
- Department of Integrative Biology, University of California, Berkeley, CA94720
| | - Cindy V. Looy
- Department of Integrative Biology, Museum of Paleontology, and Herbarium, University of California, Berkeley, CA94720
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Matsui K, Tsuihiji T. The phylogeny of desmostylians revisited: proposal of new clades based on robust phylogenetic hypotheses. PeerJ 2019; 7:e7430. [PMID: 31637114 PMCID: PMC6800978 DOI: 10.7717/peerj.7430] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 07/07/2019] [Indexed: 12/03/2022] Open
Abstract
Background Desmostylia is a clade of extinct aquatic mammals with no living members. Today, this clade is considered belonging to either Afrotheria or Perissodactyla. In the currently-accepted taxonomic scheme, Desmostylia includes two families, 10 to 12 genera, and 13–14 species. There have been relatively few phylogenetic analyses published on desmostylian interrelationship compared to other vertebrate taxa, and two main, alternative phylogenetic hypotheses have been proposed in previous studies. One major problem with those previous studies is that the numbers of characters and OTUs were small. Methods In this study, we analyzed the phylogenetic interrelationship of Desmostylia based on a new data matrix that includes larger numbers of characters and taxa than in any previous studies. The new data matrix was compiled mainly based on data matrices of previous studies and included three outgroups and 13 desmostylian ingroup taxa. Analyses were carried out using five kinds of parsimonious methods. Results Strict consensus trees of the most parsimonious topologies obtained in all analyses supported the monophyly of Desmostylidae and paraphyly of traditional Paleoparadoxiidae. Based on these results, we propose phylogenetic definitions of the clades Desmostylidae and Paleoparadoxiidae based on common ancestry.
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Affiliation(s)
- Kumiko Matsui
- The Kyushu University Museum, Kyushu University, Fukuoka, Japan.,The University Museum, The University of Tokyo, The University of Tokyo, Tokyo, Japan
| | - Takanobu Tsuihiji
- Department of Earth and Planetary Science, Graduate school of Science, The University of Tokyo, Tokyo, Japan.,Department of Geology and Paleontology, National Museum of Nature and Science, Tsukuba, Japan
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Matsui K, Kimura Y, Nagata M, Inose H, Ikeda K, Beatty BL, Obayashi H, Hirata T, Otoh S, Shinmura T, Agematsu S, Sashida K. A long-forgotten 'dinosaur' bone from a museum cabinet, uncovered to be a Japan's iconic extinct mammal, Paleoparadoxia ( Desmostylia, Mammalia). R Soc Open Sci 2018; 5:172441. [PMID: 30109064 PMCID: PMC6083731 DOI: 10.1098/rsos.172441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
Here, we report a new 'discovery' of a desmostylian fossil in the geological collection at a national university in Japan. This fossil was unearthed over 60 years ago and donated to the university. Owing to the original hand-written note kept with the fossil in combination with interview investigation, we were able to reach two equally possible fossil sites in the town of Tsuchiyu Onsen, Fukushima. Through the interviews, we learned that the fossil was discovered during construction of a debris flow barrier and that it was recognized as a 'dinosaur' bone among the locals and displayed in the Village Hall before/until the town experienced a fire disaster in 1954. As scientific findings, the fossil was identified to be a right femur of Paleoparadoxia (Desmostylia), which shows well-preserved muscle scars on the surface. The age was estimated to be 15.9 Ma or younger in zircon-dating. This study shows an excellent case that historical and scientific significances could be extracted from long-forgotten uncatalogued specimens as long as the original information is retained with the specimens.
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Affiliation(s)
- Kumiko Matsui
- Kyushu University Museum, 6-10-1 Hakozaki, Higashi-ku, Fukuoka City, 812-8581, Japan
- University Museum, the University of Tokyo, 7 Chome-3-1 Hongo, Bunkyō, Tokyo 113-0033, Japan
| | - Yuri Kimura
- Department of Geology and Paleontology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan
| | - Mitsuhiro Nagata
- Graduate School of Science and Engineering for Education, University of Toyama, Toyama 930-8555, Japan
| | - Hiroaki Inose
- Fukushima Museum, Aizu-wakamatsu, Fukushima 965-0807, Japan
| | - Kazuya Ikeda
- Tsuchiyu-Onsen Tourism Association, Tsuchiyu Onsen Town, Fukushima 960-2157, Japan
| | - Brian Lee Beatty
- Department of Anatomy, New York Institute of Technology College of Osteopathic Medicine, Northern Boulevard, Old Westbury, NY 11568, USA
| | - Hideyuki Obayashi
- Graduate School of Sciences, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Takafumi Hirata
- Geochemical Research Center, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Shigeru Otoh
- Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555, Japan
| | | | - Sachiko Agematsu
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Katsuo Sashida
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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Matsui K. How can we reliably identify a taxon based on humeral morphology? Comparative morphology of desmostylian humeri. PeerJ 2017; 5:e4011. [PMID: 29134151 PMCID: PMC5683048 DOI: 10.7717/peerj.4011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/19/2017] [Indexed: 11/20/2022] Open
Abstract
Desmostylia is a clade of marine mammals belonging to either Tethytheria or Perissodactyla. Rich fossil records of Desmostylia were found in the Oligocene to Miocene strata of the Northern Pacific Rim, especially in the northwestern region, which includes the Japanese archipelago. Fossils in many shapes and forms, including whole or partial skeletons, skulls, teeth, and fragmentary bones have been discovered from this region. Despite the prevalent availability of fossil records, detailed taxonomic identification based on fragmentary postcranial materials has been difficult owing to to our limited knowledge of the postcranial diagnostic features of many desmostylian taxa. In this study, I propose the utilization of diagnostic characters found in the humerus to identify desmostylian genus. These characters can be used to identify isolated desmostylian humeri at the genus level, contributing to a better understanding of the stratigraphic and geographic distributions of each genus.
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Affiliation(s)
- Kumiko Matsui
- Department of Geology and Paleontology, National Museum of Nature and Science, Tsukuba, Japan
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