| Plourdosteus | |
|---|---|
 | |
| Various species ofPlourdosteus, fromLate Devonian ofCanada,Russia andBaltic countries | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | †Placodermi |
| Order: | †Arthrodira |
| Suborder: | †Brachythoraci |
| Family: | †Panxiosteidae |
| Genus: | †Plourdosteus Ørvig, 1951 |
| Species | |
| |
Plourdosteus is anextinctgenus ofplacodermarthrodire which was relatively widespread inEuramerica during theGivetian toFrasnian ages of theDevonian.[1] It was a small placoderm, withP. canadensis specimen MNHM 2-177 measuring 37.5 cm (14.8 in) long.[2]
The namePlourdosteus commemorates the Plourde family atMiguasha National Park.[3]
Plourdosteus was previously assigned to thefamilyPlourdosteidae within theCoccosteomorphi. However, subsequent studies found the family Plourdosteidae to bepolyphyletic and should be dismissed.Plourdosteus was then proposed to be a member ofPanxiosteidae.[4][5] In the 2010 Carr & Hlavinphylogenetic study,Panxiosteidae was recognized as thesister taxon to the familyDunkleosteidae, which together comprised thesuperfamilyDunkleosteoidea (one of the three majorclades ofEubrachythoraci).[4]
Thephylogeny ofPlourdosteus withinPanxiosteidae is shown in thecladogram below from the 2013 Zhu & Zhu study:[5]
| Eubrachythoraci | Pachyosteomorphi | |
However, the subsequent 2016 Zhuet al. study using a largermorphological dataset recoveredPanxiosteidae well outside ofDunkleosteoidea, instead withinCoccosteomorphi and thenCoccosteoidea as thesister group ofCoccosteidae, as shown in the cladogram below:[6]
| Eubrachythoraci | |
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