Family Acastidae
Subfamilies: Asteropyginae, Acastavinae
Genera: Acastava, Acastella, Asteropyge, Bradocryphaeus, Comura, Cryphina, Delocare, Dunopyge, Gudralisium, Heliopyge, Jaylopygiella, Pseudocryphaeus?, Rhenops, Treveropyge, Wiltzops.
Acastidae (acastids) comprises two subfamilies in the Ardennes. One of these, Acastavinae, appears to be confined to the Lower Devonian. Members of Acastavinae were among the first inhabitants of the young Lochkovian sea in the Ardennes where they were represented by Acastella heberti in the Mondrepuis Formation in the Mondrepuis area.
The second subfamily, Asteropyginae, is found almost throughout the Devonian period. It is also among pioneers in the Ardennes and includes Cryphina gdoumontensis from the Lochkovian in the Gdoumont area. Among extremely rare genera is Wiltzops of which a specimen was recently found in the Upper Emsian of Marche-en-Famenne.
Asteropyge punctata is a notorious Middle Devonian member of the subfamily, records of which should be treated with care. This species has been recorded in the old literature (Asselberghs, Maillieux, etc.) from Belgium, especially from lower Eifelian strata near Vireux-Molhain ("Mur des douaniers"). In fact, like Phacops latifrons, there is currently no definite record of Asteropyge punctata from the Ardennes. A specimen was recovered from a middle Eifelian embankment near Jemelle which seems to come close to Asteropyge comes, a species that is in turn similar to A. punctata. More and better preserved material will be required to make a definite assignment.
During the Givetian Asteropgyinae is rare and until now, only a specimen is known that belongs to Gudralisium. In the Frasnian, Bradocryphaeus becomes locally abundant, being represented in Belgium by B. maillieuxi and B. vanherlei, among other species. Heliopyge is rare and only known from the direct surroundings of Nismes.
List of species
Lochkovian
- Acastella heberti (GOSSELET, 1888)
- Cryphina gdoumontensis (ASSELBERGHS, 1930)
Pragian
- Treveropyge sp.
- Pseudocryphaeus? sp.
- Dunopyge sp.
- Rhenops sp.
- Acastava sp.
Emsian
- Wiltzops cf. diadema (RICHTER, 1909)
- Treveropyge cf. wiltziana BASSE, 2003
- Delocare sp.
- Comura sp.
- Acastava sp.
Eifelian
- Jaylopygiella sp.
- Asteropyge cf. comes BASSE, 2003
- Neometacanthus sp.
Givetian
- Gudralisium sp.
Frasnian
- Bradocryphaeus maillieuxi (RICHTER & RICHTER, 1926)
- Bradocryphaeus vanherlei VAN
VIERSEN & BIGNON, 2011
- Bradocryphaeus neptuni VAN VIERSEN & BIGNON, 2011
- Bradocryphaeus sp. 20 (VAN VIERSEN & BIGNON, 2011)
- Bradocryphaeus mosanus (RICHTER & RICHTER, 1926)
- Heliopyge helios (RICHTER & RICHTER, 1926)