TABLE 1. Summary of the morphological features, which are useful to distinguish between the species of Eosemionotus.

Morphological features

E. vogeli

E. ceresiensis

E. diskosomus

E. sceltrichensis

E. minutus

Body shape fusiform fusiform deep deep fusiform
Ornamented dermal skull bones present absent absent absent absent
Length frontal process ? short long long long
Relationship between frontal processes ? coalescent coalescent coalescent separate
Supraoccipital canal in parietals present present absent absent present
Parietals fused absent absent absent present absent
Number of extrascapulars 1 pair 5 3 pairs 3 pairs 3 pairs
Maximal number of premaxillary teeth 4 6 3-4 4 6
Number of dentary teeth 7 10-12 ? ? 11
Maxillary teeth ? present absent absent present?
Shape of maxilla slender slender deep deep slender
Position of lower jaw articulation relative to orbit centre anterior anterior centre centre
Depth to length ratio of opercle ~1 ~1 >1 >1 >1
Length of interopercle short short short long ?
Number of branchiostegals 6-7 7-8 5 6 5
Number of caudal fin rays 12-15 13-15 13 12 12
Number of caudal fin rays below the lateral line 7-8 8-9 7 8 8
Size of fringing fulcra slender small large large slender
Fringing fulcra on dorsal margin of caudal fin present present present present absent
Number of scales in marginal row of body lobe 6-7 5 4 2 4
Number of scales posterodorsal to the hinge-line 4 5 4 4-5 3
Number of dorsal caudal fulcra on the body lobe 5-6 5 4 4 4
Number of vertical rows of scales 26-28 27-28 23-25 23-25 24
Dorsal precaudal scutes ? 10 7-8 absent 1
Ventral precaudal scutes absent absent absent 4 3
Number of anal fin rays 7 6 6-7 7 5
Number of dorsal fin rays 6-10 6 9 6-7 6

 

TABLE 2. Body proportions based on measurements taken on well-preserved specimens. SL: standard length, HL: head length, BD: maximal body depth, CD: minimal depth of the caudal peduncle.

Species Specimen SL HL/SL BD/SL CD/SL
E. ceresiensis PIMUZ T357 39,00 0,35 0,33 0,13
  PIMUZ T236 38,00 0,30 0,41 0,15
  PIMUZ T319 42,50 0,32 0,42 0,18
  PIMUZ T329 36,50 0,33 0,42 0,18
E. diskosomus MCSN 8082 45,00 0,37 0,58 0,20
  MCSN 8006 60,50 0,35 0,51 0,17
  MCSN 5617 46,70 0,36 0,61 0,20
  PIMUZ T2924 22,50 0,39 0,55 0,20
E. sceltrichensis MCSN 8418 52,80   0,48  
  MCSN 8497 39,14   0,45  
  MCSN 8491 33,16   0,53  
E. minutus MCSN 8482 25,00 0,39 0,38 0,18

 

TABLE 3. Fossil record of Eosemionotus.

Taxonomy Stratigraphic provenance Geographic provenance Reference
Eosemionotus sp. Carnian, Pyrenean basin Vilanova de la Sal, Lleida, Spain Fortuny et al., 2011
Eosemionotus sp. upper Ladinian, Falang Fm. (Zhuganpo Member) Changdi, Luoping, Yunnan, China Jin, 2006
Eosemionotus sp. upper Ladinian, Alcover unit Alcover, Tarragona, Spain Cartanyà, 1999
E. ceresiensis,
E. diskosomus
,
E. sceltrichensis,
E. minutus
Ladinian, Meride Limestone Several localities, Monte San Giorgio, Switzerland this work
Eosemionotus sp. lower Ladinian, Prosanto Fm. Ducan and Landwasser areas, Graubünden, Switzerland Bürgin et al., 1991; Herzog, 2003
E. ceresiensis,
E. diskosomus
lowermost Ladinian, Besano Fm. Several localities, Monte San Giorgio, Switzerland Bürgin, 2004;
this work
Eosemionotus sp. upper Anisian, Guanling Fm. (Member II) Xinmin, Panxian, Guizhou, China Jin, 2006
E. vogeli upper Anisian, Diemel Fm. (Middle Muschelkalk) Grebenberg bei Angerstein, Germany Schultze and Möller, 1986
E. vogeli upper Anisian, Heilbronn Formation, ‘blaue Fischmergel’ of Rüdersdorf (Middle Muschelkalk) Rüdersdorf bei Berlin, Germany Siegel and Wischnewsky, 2017; this work
E. vogeli upper Anisian, Karlstadt Fm. (Middle Muschelkalk) Förderstedt bei Staßfurt, Germany Fritsch, 1906
Eosemionotus sp. upper Anisian, Strelovec Fm. Robanov kot valley, Kamnik-Savinja Alps, Slovenia Miklavc et al., 2016
Eosemionotus sp. middle Anisian, Velika Planina Horizon Kamnik-Savinja Alps, Slovenia Hitij et al., 2010
Eosemionotus sp. middle Anisian, Upper Member, Guanling Fm. Dawazi site, Yunnan, China Sun et al., 2009
Eosemionotus sp. middle - upper Anisian, Vossenveld Fm. (Lower Muschelkalk) Steen- en Kalkgroeve Winterswijk, The Netherlands Oosterink and Poppe, 1979; Hagdorn and Simon, 2010; Maxwell et al., 2016