He has spent his career at the Swedish Museum of Natural History in Stockholm, Sweden, as curator at the Department of Palaeozoology.
A recurrent theme in Bjerring's research is that much of the vertebrate head is formed by a complex intertwining of serially homologous anatomical segments.
Here, Bjerring has proposed that neither alternative is correct; rather, the confusion may stem from the fact that, owing to the enormous expansion of the telencephalon in therians, one of the bone pairs has been displaced and forms the tentorium cerebelli below the skull roof.
[15] He has also analysed the basic structure of the paired limbs by comparing the pectoral and pelvic fins of the Eusthenopteron with the hindleg of the Devonian tetrapod Ichthyostega and embryonic humans.
He identified a pair of intracranial ligaments that hold their brains in place,[17] variations in the structure of the vomer,[18] the structure of the olfactory organ in bichir embryos,[19] and reported a spinobulbar cistern resembling the cerebellomedullary cistern of mammals.