Yudjaicyathus

Yudjaicyathus A. ZHURAVLEV, 1983

Specimen-type: Yudjaicyathus astashkini holotype, A. ZHURAVLEV, ZHURAVLEVA& FONIN, 1983, pl. 4, fig. 1

Systematics:
Order: AJACICYATHIDA R. Bedford& J. Bedford, 1939
Suborder: AJACICYATHINA R. Bedford& J. Bedford, 1939
Superfamily: ETHMOPHYLLOIDEA Okulitch, 1937
Family: KIJACYATHIDAE Zhuravleva, 1964

Yudjaicyathus Yudjaicyathus astashkini ZHURAVLEV holotype PIN 3848/505 Atdabanian, Bachyk Creek, Lena River, Yakutia, Russia Oblique longitudinal section (A. ZHURAVLEV, ZHURAVLEVA & FONIN, 1983)

Outer wall

• Structure of outer carcass wall (OW/SW) : Carcass wall well defined
• Carcass perforations: outer wall or single wall (OW/SW) : Canals
• Shape of carcass canals (OW/SW) : Straight
• Direction of carcass canals (OW/SW) : Upwardly opening ; Horizontal opening
  (horizontal to upwardly opening)
• Origin of carcass canals (OW/SW) : Limited to the carcass
• Relationship between carcass canals and intersept (OW/SW) : Several rows of canals per intersept
• Carcass bumps: outer wall or single wall (OW/SW) : None
• Carcass external plates: outer wall or single wall (OW/SW) : Present
• Type of carcass external plates (OW/SW) : Bracts
• Shape of carcass external plates (OW/SW) : Planar ; Arcuate
• Direction of carcass external plates (OW/SW) : Downwardly projecting
• Stipules : ?
• Type of morphological tubes (OW/SW) : Inverted-V shaped
• Additional sheath : None

Inner wall

• Structure of inner carcass wall (IW) : Carcass wall well defined
• Stipules : ?
• Carcass perforations: inner wall (IW) : Pores
• Type of carcass pores (IW) : Simple
• Relationship between rows of carcass pores and intersept (IW) : 1
• Relationship between rows of carcass pores and tabulae (IW) : ?
• Building of carcass perforations (IW) : Without participation of vertical structures
• Carcass external plates: inner carcass wall (IW) : Present
• Type of carcass external plates (IW) : Annuli
• Relationship between carcass annuli and tabulae (IW) : Annuli between each tabulae
• Shape of carcass external plates (IW) : S-shaped
• Direction of carcass external plates (IW) : Upwardly projecting
• Type of morphological tubes (IW) : None
• Additional sheath : None

Intervallum

• Vertical intervallar structures : Present
• Type of vertical intervallar structures : Septa
• Repartition of vertical intervallar structures pores : Completely porous
• Porosity of vertical intervallar structures : ?
• Pores of vertical intervallar structures : Circular pores
• Link between vertical intervallar structures : None
• Intervallar cells : None
• Tabulae : Present ; none
  (pectinate tabulae may be present)
• Building of tabulae : Independent from walls
• Porosity of tabulae : Pecten
  (pectinate tabulae may be present)

Others informations

• Cup shapes : Cylindrical-conical
• Shape of cup bulges : None
• Number of walls : 2
• Habitus : Solitary ; Modular
• Type of modularity : Branching by longitudinal subdivisions ; Catenulate
• Central Cavity (or internal if one wall) : Empty
• Thorny corolla : None
• Chambers : None
• Other aquiferous unit : None
• Stratigraphical extension : Atdabanian
• Atdabanian : 3 ; 4
• Geographical repartition : Russia
• Russia : Siberian Platform

Systematic

• Orders : Ajacicyathida
• Suborders inside the Ajacicyathida : Ajacicyathina
• Superfamillies inside the Ajacicyathina : Ethmophylloidea
• Famillies inside the Ajacicyathina : Kijacyathidae

External view

• Cup shapes : Cylindrical-conical
• Shape of cup bulges : None
• Structure of outer carcass wall (OW/SW) : Carcass wall well defined
• Structure of inner carcass wall (IW) : Carcass wall well defined
• Habitus : Solitary ; Modular
• Type of modularity : Branching by longitudinal subdivisions ; Catenulate
• Carcass bumps: outer wall or single wall (OW/SW) : None
• Carcass external plates: outer wall or single wall (OW/SW) : Present
• Type of carcass external plates (OW/SW) : Bracts
• Shape of carcass external plates (OW/SW) : Planar ; Arcuate
• Direction of carcass external plates (OW/SW) : Downwardly projecting
• Carcass external plates: inner carcass wall (IW) : Present
• Type of carcass external plates (IW) : Annuli
• Relationship between carcass annuli and tabulae (IW) : Annuli between each tabulae
• Shape of carcass external plates (IW) : S-shaped
• Direction of carcass external plates (IW) : Upwardly projecting
• Additional sheath : None
• Thorny corolla : None

Transverse section

• Shape of cup bulges : None
• Number of walls : 2
• Structure of outer carcass wall (OW/SW) : Carcass wall well defined
• Structure of inner carcass wall (IW) : Carcass wall well defined
• Habitus : Solitary ; Modular
• Central Cavity (or internal if one wall) : Empty
• Carcass perforations: outer wall or single wall (OW/SW) : Canals
• Relationship between carcass canals and intersept (OW/SW) : Several rows of canals per intersept
• Carcass bumps: outer wall or single wall (OW/SW) : None
• Carcass external plates: outer wall or single wall (OW/SW) : Present
• Carcass perforations: inner wall (IW) : Pores
• Building of carcass perforations (IW) : Without participation of vertical structures
• Carcass external plates: inner carcass wall (IW) : Present
• Additional sheath : None
• Thorny corolla : None
• Vertical intervallar structures : Present
• Type of vertical intervallar structures : Septa
• Repartition of vertical intervallar structures pores : Completely porous
• Link between vertical intervallar structures : None
• Intervallar cells : None
• Tabulae : Present ; none
  (pectinate tabulae may be present)
• Porosity of tabulae : Pecten
  (pectinate tabulae may be present)
• Other aquiferous unit : None

Longitudinal section

• Shape of cup bulges : None
• Number of walls : 2
• Structure of outer carcass wall (OW/SW) : Carcass wall well defined
• Structure of inner carcass wall (IW) : Carcass wall well defined
• Habitus : Solitary ; Modular
• Type of modularity : Branching by longitudinal subdivisions ; Catenulate
• Central Cavity (or internal if one wall) : Empty
• Carcass perforations: outer wall or single wall (OW/SW) : Canals
• Shape of carcass canals (OW/SW) : Straight
• Direction of carcass canals (OW/SW) : Upwardly opening ; Horizontal opening
  (horizontal to upwardly opening)
• Origin of carcass canals (OW/SW) : Limited to the carcass
• Relationship between carcass canals and intersept (OW/SW) : Several rows of canals per intersept
• Carcass bumps: outer wall or single wall (OW/SW) : None
• Carcass external plates: outer wall or single wall (OW/SW) : Present
• Type of carcass external plates (OW/SW) : Bracts
• Shape of carcass external plates (OW/SW) : Planar ; Arcuate
• Direction of carcass external plates (OW/SW) : Downwardly projecting
• Stipules : ?
• Type of morphological tubes (OW/SW) : Inverted-V shaped
• Carcass perforations: inner wall (IW) : Pores
• Relationship between rows of carcass pores and tabulae (IW) : ?
• Carcass external plates: inner carcass wall (IW) : Present
• Type of carcass external plates (IW) : Annuli
• Relationship between carcass annuli and tabulae (IW) : Annuli between each tabulae
• Shape of carcass external plates (IW) : S-shaped
• Direction of carcass external plates (IW) : Upwardly projecting
• Type of morphological tubes (IW) : None
• Additional sheath : None
• Thorny corolla : None
• Vertical intervallar structures : Present
• Type of vertical intervallar structures : Septa
• Repartition of vertical intervallar structures pores : Completely porous
• Porosity of vertical intervallar structures : ?
• Pores of vertical intervallar structures : Circular pores
• Link between vertical intervallar structures : None
• Intervallar cells : None
• Tabulae : Present ; none
  (pectinate tabulae may be present)
• Building of tabulae : Independent from walls
• Chambers : None
• Other aquiferous unit : None

Oblique section

• Shape of cup bulges : None
• Number of walls : 2
• Structure of outer carcass wall (OW/SW) : Carcass wall well defined
• Structure of inner carcass wall (IW) : Carcass wall well defined
• Habitus : Solitary ; Modular
• Central Cavity (or internal if one wall) : Empty
• Carcass perforations: outer wall or single wall (OW/SW) : Canals
• Shape of carcass canals (OW/SW) : Straight
• Direction of carcass canals (OW/SW) : Upwardly opening ; Horizontal opening
  (horizontal to upwardly opening)
• Origin of carcass canals (OW/SW) : Limited to the carcass
• Relationship between carcass canals and intersept (OW/SW) : Several rows of canals per intersept
• Carcass bumps: outer wall or single wall (OW/SW) : None
• Carcass external plates: outer wall or single wall (OW/SW) : Present
• Stipules : ?
• Type of morphological tubes (OW/SW) : Inverted-V shaped
• Carcass perforations: inner wall (IW) : Pores
• Relationship between rows of carcass pores and intersept (IW) : 1
• Relationship between rows of carcass pores and tabulae (IW) : ?
• Building of carcass perforations (IW) : Without participation of vertical structures
• Carcass external plates: inner carcass wall (IW) : Present
• Type of morphological tubes (IW) : None
• Additional sheath : None
• Thorny corolla : None
• Vertical intervallar structures : Present
• Type of vertical intervallar structures : Septa
• Repartition of vertical intervallar structures pores : Completely porous
• Porosity of vertical intervallar structures : ?
• Pores of vertical intervallar structures : Circular pores
• Link between vertical intervallar structures : None
• Intervallar cells : None
• Tabulae : Present ; none
  (pectinate tabulae may be present)
• Building of tabulae : Independent from walls
• Porosity of tabulae : Pecten
  (pectinate tabulae may be present)
• Chambers : None
• Other aquiferous unit : None

Tangential section

• Type of carcass pores (IW) : Simple
• Thorny corolla : None
• Repartition of vertical intervallar structures pores : Completely porous
• Porosity of vertical intervallar structures : ?
• Pores of vertical intervallar structures : Circular pores
• Porosity of tabulae : Pecten
  (pectinate tabulae may be present)