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The Skeleton
after a Lithograph by J.F.Brandt
1. The Skull
the Dresden skull

after an etching
Chewing Plates

Apparently no hyoid bone (Adam's apple) has been collected, although it was probably present.






A horny chewing plate each in the upper and lower jaw
"with many winding wavy canals, and between them are eminences which fit into the canals of the corresponding bone". (Steller)
2. Postcranial

the Dresden Specimen
As a rule the skeletons in the museums consist of bones collected from the beach deposits of Bering Island, or rather from the butchering fields from middle 18th century. They were assembled, attempting to create plausible overall specimen, and hoping that the number of bones were those of the living animal.

1742 Steller himself examined, measured and counted the bones of a female seacow on Bering Island, but some of his figures are doubtful. Steller e.g. counted six cervical vertebrae. All mammals however own seven, except Sloth (9) and Manatees (6). As Steller believed that he was dealing with a Manatee (which he knew from Spanish records), this had probably influenced his judgment and he counted the 7th cervival as 1st thoratic.

1982 Ann Forsten and Phillip M. Youngman described the Helsinki skeleton. As this is presumably the only specimen coming entirely from one individual, their paper is often referred to. In the same year Adolf Kleinschmidt described the Braunschweig specimen. And 2003 Clara Stefen studied the Dresden skeleton.

The following table compares the results of these papers:
  Steller Forsten +
Youngman		 Kleinschmidt Stefen
cervical 6 7 7 7
thoratic 19 17 19 18
lumbar   3 8 3
sacrum   1    
caudal 35 34 26 missing
Total 60 62 60 n/a
pairs of ribs 17 17 19 18

 

Shoulder belt/arms
H. gigas had no clavicles.

Steller wrote: radius and ulna terminate bluntly with tarsus and metatarsus (rather carpal and metacarpal). It can be assumed that the carpalia were extremely reduced, however none has been collected. The animal had no finger bones, these had disappeared during its evolution. the carpal bones were covered with solid fat, and the surrounding skin was much thicker, so the ends of the arms were like a hooked horses hoof, covered with strong bristles.

Sternum
According to Steller the first five pairs of ribs were joined to the sternum by cartilage. The sternum in the upper portion, where the ribs are fastened on is cartilaginous, the lower portion is bony . Only few specimen of this bone are left.

Only the Natural History Museum Helsinki attempted to show these first pairs of ribs attached to the sternum.

The further 12 pairs of ribs were free, permitting a large respiratory volume. The ribs are thick and heavy.

The Khabarovsk specimen
(Photo Evgeniy Novomodniy)
mouse over image for more information
The Pelvis
Pelvis regressed to two small bones, "in size and shape like the ulna of the human skeleton ... joined with very strong ligaments to the thirty-fifth vertebra" (Steller). Of this bone five specimen are kept in museums:


(Dresden specimen) Lumbar and Tail Vertebra
The lumbar and tail vertebrae are heavy, the transverse processes long and strong.
These processes are on some occasions not connected to their vertebra. Frequently they have been found singularly or are missing. Occasionally they have been mistaken for metacarpal. (Kleinschmidt 1951, Domning 1978).
The dorsal processes are less prominent.