transitional fossil

noun

: a fossil that exhibits characteristics of both ancestral and derived forms
During the past 30 years, new discoveries and reinvestigations of long-forgotten specimens have coalesced into a flood of transitional fossils. Paleontologists have unearthed walking whales from Pakistan, feathered dinosaurs from China … Courier News (Bridgewater, New Jersey), 27 Feb. 2011
However, although the mammal and bird origins are both documented by numerous transitional fossils, turtles appear abruptly. Michael S. Y. Lee, Science, 24 Sept. 1993

Word History

First Known Use

1850, in the meaning defined above

Time Traveler
The first known use of transitional fossil was in 1850

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Dictionary Entries Near transitional fossil

Cite this Entry

“Transitional fossil.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/transitional%20fossil. Accessed 6 Dec. 2022.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!


The Great British Vocabulary Quiz

  • union jack speech bubble
  • Named after Sir Robert Peel, what are British police called?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ