Cormorants are sleek, large to medium-sized, long-necked waterbirds. The typical body length is 19-40 in (48-102 cm) and they weigh 1.5-7.7 lb (0.7-3.5 kg). The wings are relatively short and angular, and the spread tail is long and wedge-shaped.
Cormorants are well adapted to flying and swimming, but because their legs are placed well-back on the body, they are rather clumsy when walking. When in the water, cormorants sit rather low because their bones are quite dense, with few air spaces, and
their feathers are not well-oiled and so get wet when immersed. The bill of cormorants is rather thin and tubular, hooked at the tip, and is lacking in external nares (or nostrils); the edges of the bill have tooth-like serrations. The head and upper
neck have powerful muscles for closing the bill; these originate in part from special long, sesamoid bones behind the back of the head and are used to maintain a tight grip on slippery fish that have been caught (the beak serrations are also useful in
this regard).

Anhingas are even sleeker, longer-necked waterbirds than cormorants. The typical body length is 34-36 in (86-92 cm). The bill is long, sharply pointed, and bright yellow. The wings are relatively short and rounded, and the long tail is wedge-shaped when
spread. The legs are placed well-back on the body. The sexes differ in both plumage and aspects of behavior. Anhingas are skilled at flying and swimming, but are clumsy on land. Like cormorants, anhingas sit low in the water because of their dense bones
and feathers that get wet when immersed.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Op vrijdag 16 september 2022 om 14:19:03 UTC+2 schreef DD'eDeN aka note/nickname/alas_my_loves:

Cormorants are sleek, large to medium-sized, long-necked waterbirds. The typical body length is 48-102 cm, they weigh 0.7-3.5 kg. The wings are relatively short and angular, and the spread tail is long and wedge-shaped. Cormorants are well adapted to

flying & swimming, but because their legs are placed well-back on the body, they are rather clumsy when walking. When in the water, cormorants sit rather low because their bones are quite dense, with few air spaces, and their feathers are not well-oiled
and so get wet when immersed. The bill of cormorants is rather thin and tubular, hooked at the tip, and is lacking in external nares (or nostrils); the edges of the bill have tooth-like serrations. The head and upper neck have powerful muscles for
closing the bill; these originate in part from special long, sesamoid bones behind the back of the head and are used to maintain a tight grip on slippery fish that have been caught (the beak serrations are also useful in this regard).

Anhingas are even sleeker, longer-necked waterbirds than cormorants. The typical body length is 34-36 in (86-92 cm). The bill is long, sharply pointed, and bright yellow. The wings are relatively short and rounded, and the long tail is wedge-shaped

when spread. The legs are placed well-back on the body. The sexes differ in both plumage and aspects of behavior. Anhingas are skilled at flying and swimming, but are clumsy on land. Like cormorants, anhingas sit low in the water because of their dense
bones and feathers that get wet when immersed.


Yes, AFAWK, all shallow-diving tetrapods evolve pachyosteosclerosis (POS) initially,
and conversely, POS is only seen in shallow-diving tetrapods.
Without POS, comorants (flying!) were unable to dive well.

Deeper diving & faster diving tetrapods OTOH evolve lightly-build skeletons: Cetacea & Pinnipedia, vs.Sirenia.

H.erectus had POS: they frequently dived for shellfish,
google e.g. "Joordens Munro engravings".
Neandertals had less POS: perhaps they waded more frequently, or more in fresh water:
not unlikely, they seasonally followed the Meuse, Rhine etc. inland (salmon trek?).
H.sapiens lost POS when we evolved from diving to wading-walking.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Friday, September 16, 2022 at 8:19:03 AM UTC-4, DD'eDeN aka note/nickname/alas_my_loves wrote:

Cormorants are sleek, large to medium-sized, long-necked waterbirds. The typical body length is 19-40 in (48-102 cm) and they weigh 1.5-7.7 lb (0.7-3.5 kg). The wings are relatively short and angular, and the spread tail is long and wedge-shaped.

Cormorants are well adapted to flying and swimming, but because their legs are placed well-back on the body, they are rather clumsy when walking. When in the water, cormorants sit rather low because their bones are quite dense, with few air spaces, and
their feathers are not well-oiled and so get wet when immersed. The bill of cormorants is rather thin and tubular, hooked at the tip, and is lacking in external nares (or nostrils); the edges of the bill have tooth-like serrations. The head and upper
neck have powerful muscles for closing the bill; these originate in part from special long, sesamoid bones behind the back of the head and are used to maintain a tight grip on slippery fish that have been caught (the beak serrations are also useful in
this regard).

Anhingas are even sleeker, longer-necked waterbirds than cormorants. The typical body length is 34-36 in (86-92 cm). The bill is long, sharply pointed, and bright yellow. The wings are relatively short and rounded, and the long tail is wedge-shaped

when spread. The legs are placed well-back on the body. The sexes differ in both plumage and aspects of behavior. Anhingas are skilled at flying and swimming, but are clumsy on land. Like cormorants, anhingas sit low in the water because of their dense
bones and feathers that get wet when immersed.

While riding on the bike path this morning, I watched an anhinga swim horizontally with body submerged, only its head and neck above the surface, it did indeed resemble a snake. Seems odd that its feathers are poorly oiled, not waterproof, since it eats
oily fish. I wonder if penguin feathers are oily.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)