期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 116, 期 6, 页码 2146-2151出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1814794116
关键词
Myxinoidea; cyclostome; monophyly; synchrotron; soft tissue
资金
- National Science Foundation [0917922, 1541491]
- National Engineering and Sciences Research Council [RGPIN 04863, RGPAS 462299, RGPIN 04715]
- Science and Technology Facilities Council [ST/M001814/1]
- U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences [DE-AC02-765F00515]
- DOE Office of Biological and Environmental Research
- National Institutes of Health (NIH), National Institute of General Medical Sciences (NIGMS) [P41GM103393]
- NERC [NE/J023426/1] Funding Source: UKRI
- STFC [ST/K001469/1, ST/M001814/1] Funding Source: UKRI
- Direct For Biological Sciences
- Division Of Environmental Biology [1541491] Funding Source: National Science Foundation
- Division Of Environmental Biology
- Direct For Biological Sciences [0917922] Funding Source: National Science Foundation
Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: (i) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or (ii) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological-molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据