superorder Ratitae
Học thuậtThân thiện
Definition
Noun: - A taxonomic group used in historical biological classification systems: "Superorder Ratitae" was a scientific term employed in older taxonomic schemes to collectively categorize all flightless birds possessing a flat, keel-less breastbone (ratites). This grouping is now considered obsolete in modern ornithological classification.
Usage Notes
- This term is highly specialized and historical. It is primarily encountered in academic texts discussing the history of biological taxonomy or in older scientific literature.
- It is not used in everyday language, modern bird guides, or current scientific discourse, where more precise phylogenetic classifications are standard.
- The term functions as a proper noun, often capitalized: .
Examples
- In historical context:
- In the 19th century, the Superorder Ratitae was proposed to unite ostriches, emus, rheas, cassowaries, and kiwis based on shared anatomical features.
- The classification scheme that included the Superorder Ratitae has been superseded by cladistic methods.
Advanced / Technical Usage
- The concept of "Ratitae" (ratites) as a monophyletic group (a group sharing a common ancestor) is still valid in modern biology, but its ranking as a "superorder" and its specific membership have been revised. Contemporary taxonomy places these birds within the infraclass Palaeognathae.
Variants and Related Words
- Ratite (noun/adjective): Referring to any flightless bird with a flat breastbone, such as an ostrich or emu. This is the modern, commonly used term for the birds once grouped in the Superorder Ratitae.
- The ostrich is a large ratite native to Africa.
- Palaeognathae (noun): The modern infraclass that includes both flightless ratites (like ostriches) and flighted tinamous, representing the current scientific understanding of this bird lineage.
Synonyms
- Historical synonym: None that are exact. In outdated classifications, it was the formal name for the group.
- Conceptual synonym (modern): The ratite birds (as a descriptive, not taxonomic, grouping).
Antonyms
- Carinatae: An obsolete taxonomic group used in contrast to Ratitae, encompassing birds with a keeled breastbone (carina), which includes most flying birds.
Noun
- used in former classifications to include all ratite bird orders