amniote
noun
am·ni·ote
ˈam-nē-ˌōt 
: any of a group (Amniota) of vertebrates that undergo embryonic or fetal development within an amnion and include the birds, reptiles, and mammals
amniote
adjective
Examples of amniote in a Sentence
Recent Examples on the Web
The transition occurred partly because amniotes evolved to reproduce with hard-shelled, rather than soft-shelled, eggs.
—
Ashley Strickland, CNN Money, 22 May 2025
The scientists dated the fossil to between 354 million and 359 million years ago, which would mean that amniotes existed at least 35 million years earlier than previously thought.
—Sara Hashemi, Smithsonian Magazine, 19 May 2025
Earliest amniote tracks recalibrate the timeline of tetrapod evolution
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues.
—Paul Smaglik, Discover Magazine, 14 May 2025
Previously, the earliest amniote fossils dated back to about 320 million years old to the late Carboniferous.
—Laura Baisas, Popular Science, 14 May 2025
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Ashley Strickland, CNN Money, 22 May 2025
The scientists dated the fossil to between 354 million and 359 million years ago, which would mean that amniotes existed at least 35 million years earlier than previously thought.
—Sara Hashemi, Smithsonian Magazine, 19 May 2025
Earliest amniote tracks recalibrate the timeline of tetrapod evolution
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues.
—Paul Smaglik, Discover Magazine, 14 May 2025
Previously, the earliest amniote fossils dated back to about 320 million years old to the late Carboniferous.
—Laura Baisas, Popular Science, 14 May 2025
Cite this Entry
“Amniote.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/amniote. Accessed 9 Sep. 2025.
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