Definition of placoid in English:

placoid

adjective ˈplakɔɪdˈplækɔɪd

Zoology

(of fish scales) toothlike, being made of dentine with a pointed backward projection of enamel, as in sharks and rays.
〔动〕（鱼鳞）板状的。比较CTENOID 和GANOID
Compare with ctenoid and ganoid
Example sentencesExamples
- It is an axiom of this theory that hard-tissue units (odontodes in the sense of Orvig 1977) comparable in structure to placoid scales can be inferred to have developed in a directly comparable manner.
- The basic odontode unit is identical to the placoid scale of chondrichthyans [SA04] [S + 98].
- Similar attempts had been underway in the dermal skeleton, stemming from Williamson's use of placoid scales from extant sharks as conceptual units in comparative analysis.
- Like other sharks, catsharks are covered with placoid scales.
- The earliest attempts to unravel the nature of development and patterning of the vertebrate dermoskeleton and visceral skeleton place central importance upon the nature of the placoid scales in living sharks.

Origin

Mid 19th century: from Greek plax, plak- 'flat plate' + -oid.

Definition of placoid in US English:

placoid

adjectiveˈplakoidˈplækɔɪd

Zoology

(of fish scales) toothlike, being made of dentin with a pointed backward projection of enamel, as in sharks and rays.
〔动〕（鱼鳞）板状的。比较CTENOID 和GANOID
Compare with ctenoid and ganoid
Example sentencesExamples
- Like other sharks, catsharks are covered with placoid scales.
- It is an axiom of this theory that hard-tissue units (odontodes in the sense of Orvig 1977) comparable in structure to placoid scales can be inferred to have developed in a directly comparable manner.
- Similar attempts had been underway in the dermal skeleton, stemming from Williamson's use of placoid scales from extant sharks as conceptual units in comparative analysis.
- The basic odontode unit is identical to the placoid scale of chondrichthyans [SA04] [S + 98].
- The earliest attempts to unravel the nature of development and patterning of the vertebrate dermoskeleton and visceral skeleton place central importance upon the nature of the placoid scales in living sharks.

Origin

Mid 19th century: from Greek plax, plak- ‘flat plate’ + -oid.

单词	placoid
释义	Definition of placoid in English: placoid adjective ˈplakɔɪdˈplækɔɪd Zoology (of fish scales) toothlike, being made of dentine with a pointed backward projection of enamel, as in sharks and rays. 〔动〕（鱼鳞）板状的。比较CTENOID 和GANOID Compare with ctenoid and ganoid Example sentencesExamples It is an axiom of this theory that hard-tissue units (odontodes in the sense of Orvig 1977) comparable in structure to placoid scales can be inferred to have developed in a directly comparable manner. The basic odontode unit is identical to the placoid scale of chondrichthyans [SA04] [S + 98]. Similar attempts had been underway in the dermal skeleton, stemming from Williamson's use of placoid scales from extant sharks as conceptual units in comparative analysis. Like other sharks, catsharks are covered with placoid scales. The earliest attempts to unravel the nature of development and patterning of the vertebrate dermoskeleton and visceral skeleton place central importance upon the nature of the placoid scales in living sharks. Origin Mid 19th century: from Greek plax, plak- 'flat plate' + -oid. Definition of placoid in US English: placoid adjectiveˈplakoidˈplækɔɪd Zoology (of fish scales) toothlike, being made of dentin with a pointed backward projection of enamel, as in sharks and rays. 〔动〕（鱼鳞）板状的。比较CTENOID 和GANOID Compare with ctenoid and ganoid Example sentencesExamples Like other sharks, catsharks are covered with placoid scales. It is an axiom of this theory that hard-tissue units (odontodes in the sense of Orvig 1977) comparable in structure to placoid scales can be inferred to have developed in a directly comparable manner. Similar attempts had been underway in the dermal skeleton, stemming from Williamson's use of placoid scales from extant sharks as conceptual units in comparative analysis. The basic odontode unit is identical to the placoid scale of chondrichthyans [SA04] [S + 98]. The earliest attempts to unravel the nature of development and patterning of the vertebrate dermoskeleton and visceral skeleton place central importance upon the nature of the placoid scales in living sharks. Origin Mid 19th century: from Greek plax, plak- ‘flat plate’ + -oid.
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