Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Cranial Bones: Lateral View01:27

Cranial Bones: Lateral View

7.7K
The lateral view of the cranium is dominated by temporal, sphenoid, and ethmoid bones.
The temporal bone forms the lower lateral side of the skull. The temporal bone is subdivided into several regions. The flattened upper portion is the squamous portion of the temporal bone. Below this area and projecting anteriorly is the zygomatic process of the temporal bone, which forms the posterior portion of the zygomatic arch. Posteriorly is the mastoid portion of the temporal bone. Projecting...
7.7K
The Fossil Record02:56

The Fossil Record

28.1K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
28.1K
Cranial Bones: Superior and Posterior View01:14

Cranial Bones: Superior and Posterior View

8.4K
The superior view of the cranium shows the frontal and paired parietal bones.
The frontal bone is the single bone that forms the forehead. At its anterior midline, between the eyebrows, there is a slight depression called the glabella. The frontal bone also forms the supraorbital margin of the orbit. Near the middle of this margin is the supraorbital foramen, the opening that provides passage for a sensory nerve to the forehead. The frontal bone is thickened just above each supraorbital margin,...
8.4K
Tooth Anatomy01:21

Tooth Anatomy

2.5K
The human tooth enables us to eat a variety of foods, speak clearly, and even aid in shaping our faces. Teeth are composed of various elements that work together. Here's a detailed look at the anatomy of a human tooth.
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
2.5K
Convergent Evolution01:54

Convergent Evolution

34.1K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
34.1K
Neurulation01:30

Neurulation

46.9K
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the...
46.9K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The identification of a novel HIV-1 CRF01_AE/B recombinant using the near full length genome in Jiangsu Province, China.

AIDS research and human retroviruses·2014
Same author

Family clusters of avian influenza A H7N9 virus infection in Guangdong Province, China.

Journal of clinical microbiology·2014
Same author

Dopamine release from transplanted neural stem cells in Parkinsonian rat striatum in vivo.

Proceedings of the National Academy of Sciences of the United States of America·2014
Same author

Delivering sound energy along an arbitrary convex trajectory.

Scientific reports·2014
Same author

Reduced expression of SRY-box containing gene 17 correlates with an unfavorable melanoma patient survival.

Oncology reports·2014
Same author

The beneficial fungus Piriformospora indica protects Arabidopsis from Verticillium dahliae infection by downregulation plant defense responses.

BMC plant biology·2014

Related Experiment Video

Updated: Mar 12, 2026

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
08:02

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton

Published on: May 7, 2016

10.4K

A Silurian maxillate placoderm illuminates jaw evolution.

Min Zhu1,2, Per E Ahlberg3, Zhaohui Pan4,2

  • 1Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China. zhumin@ivpp.ac.cn per.ahlberg@ebc.uu.se.

Science (New York, N.Y.)
|November 16, 2016
PubMed
Summary

A new Silurian placoderm discovery clarifies the evolution of jaw bones. Maxilla, premaxilla, and dentary bones in placoderms are homologous to gnathal plates, revealing a shared dental arcade origin.

More Related Videos

Author Spotlight: Insights into an Efficient Murine Maxillary Orthodontic Model Protocol
04:11

Author Spotlight: Insights into an Efficient Murine Maxillary Orthodontic Model Protocol

Published on: October 27, 2023

1.4K
Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras
09:38

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

Published on: May 31, 2014

11.5K

Related Experiment Videos

Last Updated: Mar 12, 2026

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
08:02

Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton

Published on: May 7, 2016

10.4K
Author Spotlight: Insights into an Efficient Murine Maxillary Orthodontic Model Protocol
04:11

Author Spotlight: Insights into an Efficient Murine Maxillary Orthodontic Model Protocol

Published on: October 27, 2023

1.4K
Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras
09:38

Assessing Species-specific Contributions To Craniofacial Development Using Quail-duck Chimeras

Published on: May 31, 2014

11.5K

Area of Science:

  • Paleontology
  • Vertebrate Evolution
  • Comparative Anatomy

Background:

  • The discovery of Entelognathus in Silurian strata presented maxilla, premaxilla, and dentary bones in a placoderm, challenging previous classifications.
  • The homology between these marginal jaw bones and the gnathal plates of other placoderms, traditionally considered the inner dental arcade, remained unresolved.
  • Understanding this relationship is crucial for tracing the evolutionary origins of jaw structures in vertebrates.

Purpose of the Study:

  • To investigate the evolutionary link between the gnathal plates of placoderms and the marginal jaw bones (maxilla, premaxilla, dentary) found in some Silurian placoderms.
  • To clarify the homology of these jaw elements and their contribution to the early dental arcade.
  • To reconstruct the transformation process of jaw structures during vertebrate evolution.

Main Methods:

  • Analysis of a newly discovered Silurian maxillate placoderm specimen.
  • Comparative morphological analysis of jaw elements between different placoderm groups and early osteichthyans.
  • Phylogenetic bracketing to infer homology and evolutionary relationships.

Main Results:

  • The newly described placoderm exhibits intermediate jaw characteristics, bridging the gap between typical placoderm gnathal plates and maxillate jaw structures.
  • Evidence suggests that the maxilla, premaxilla, and dentary in these Silurian placoderms are homologous to the gnathal plates of other placoderms.
  • The study indicates that the transformation from gnathal plates to maxillate bones occurred simultaneously in both upper and lower jaws.

Conclusions:

  • The maxilla, premaxilla, and dentary are integrated into the placoderm dental arcade, suggesting a shared evolutionary origin with gnathal plates.
  • This gnathal-maxillate transformation predates the evolution of infradentary bones in the lower jaw.
  • The findings provide critical insights into the early evolution of jaw apparatus in vertebrates, particularly the transition towards osteichthyan-like jaw structures.