| Holdenius | |
|---|---|
 | |
| Artist's reconstruction ofHoldenius holdeni and its prey, an unidentifiedCtenacanthchondrichthyan | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | †Placodermi |
| Order: | †Arthrodira |
| Suborder: | †Brachythoraci |
| Clade: | †Eubrachythoraci |
| Clade: | †Pachyosteomorphi |
| Clade: | †Aspinothoracidi |
| Genus: | †Holdenius Dunkle and Bungart, 1942 |
| Type species | |
| Holdenius holdeni Dunkle and Bungart, 1942 | |
Holdenius is anextinctgenus ofarthrodireplacoderm fish which lived during the LateDevonian period.
Holdenius was a large arthrodire, reaching lengths of around 3 m (9.8 ft).[1] This placoderm is known only from isolated jaw bones,[2] and little is known about it except that it is relativelymorphologically similar to its more famous relativeDunkleosteus, with which it shared a spatial and temporal range.
Holdenius was apiscivorous animal that used its sharp shearing gnathal plates to seize and cleave its prey into manageable pieces. One articulated specimen of this placoderm from the Upper DevonianCleveland Shale was preserved adjacent to the remains of its prey; aCtenacanthchondrichthyan, which had been bitten in half. Considering its prey was over half its size, it can be inferred thatHoldenius was an exceptionally aggressivenektonic predator. An anteriordorsal spine from the ctenacanth was found lodged in thepalate and extending into the braincase of theHoldenius, likely killing it instantly.[3]
Holdenius is amonospecific genus. Previously classified as belonging to thefamilyDunkleosteidae, it is now considered to be a member ofAspinothoracidi, thesisterclade toDunkleosteoidea.[4]
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