1.Earliest moose - Libralces gallicus
This earliest species of moose ("Weighing Scale Elk") - estimated some 2,6 million years ago in the Pliocene period - had the size comparable to small moose bulls today and looked . It had the face of a deer (not the typical moose muzzle !) and the body of a plains runner. He likely lived in Europe.
Libralces gallicus had antlers with palms on the ends of really long rods (larger 2m) - quite odd-looking thing reminding a comic drawing more than a real animal's antlers.
2. American stag moose - Cervalces scotti
Sized as today's larger Alaskan moose the Stag Moose had a deer-like face and
a body similar to today's moose. His antlers were larger and more complex,
less palmated and with plates shaped like trumpets.
While the base sticked out straight from each side of the head, the branches stood in all directions. The name "stag" already shows the similarities to deer/elk in the outlook.
While he was known to be in North America more than 25.000 years ago, he was extinct in the end of the last ice-age, around 10.000-12.000 years ago, and was "replaced" by the broad-fronted moose coming over the Bering-strait (who likely co-existed with Cervalces scotti for quite some time).
Cervalces Scotti lived in North-America in the Pleistocene period, which was ruled these days by predators - not the lack of food supply was any problem, but the survival against all those predators.
This species already had long legs to escape predators and also wide-spreading hooves to walk in the shallows of lakes common that time. The antlers were huge, but not the bones and muscles for using them. This gives the impression, that more show than fight got important.
Who survived, had an abundance of high quality food- the nose, muzzle or teeth therefore didn't need to be specialized - an outcome of the predator-ruled environment in North-America these days in the Pleistocene.
The stag moose's habitat was likely down to South Carolina, Arkansas and Oklahoma that time, hence he was living in a different habitat than today's moose, whose propagation in Southern direction is much lower.
The lifestyle might have been very similar to that of modern moose.
Fossils were found e.g. in Alaska, New Jersey, Illinois, Ontario and Virginia.
3. Broad-fronted moose - Alces latifrons - the start of modern moose with moose nose
Lived in Eurasia and co-existed with Cervalces scotti, but took over it's position in North-America, after the latter died out.
Between ice ages, some 700,000-900,000 years ago, moose came back as giants with long legs, larger and much heavier than today's Alaskan moose - likely double the body mass than the largest modern moose. They were called the broad-fronted moose. The very largest males weighed close to two tons! They had teeth similar to modern moose - but much larger.
His nose looked similar a deer, but also bigger with larger lips and a mobile nose known for foliage feeders and browsers -> moose started to specialise in certain foods after feeding, and looking, like normal deer for millions of years !
They had huge antlers, which served more for show than for fighting. Antlers became important symbols - "luxury organs" - which were selection criteria for the cows to decide which males to breed with. Huge antlers showed good breeding stock and good genes - giving a good chance for the emerging calves to grow up fast and have therefore a better chance to survive : The main principle of evolutionary theory: Only the strongest survive. And if a bull has enough energy left to grow such tremendous antlers, he must have good genes, e.g. for finding good food supply ! (Transferred to us humans, this would be comparable to having a bulging wallet and a good job :-). All this was also valid for the stag moose.
Despite the absolute size of the antlers of broad-fronted moose, they were relatively shorter (shorter beams, larger palms, longer tines) and lighter than those of it's predecessors. This leads to the conclusion that broad-fronted moose more looked for cover and left the open plains, requiring antlers handier for making its way through forest.
After a time when all herbivores and carnivores were extraordinarily large, all species started shrinking due to dwindling supplies of high-quality food - likewise the broad-fronted moose.
In the Pleistocene in Eurasia, where the broad-fronted moose existed, the environment was marked by a relative food shortage, but with fewer predators if compared to North-America. Most species became much smaller and developed more complex teeth to better exploit their little food - NOT THE MOOSE !
He "chose" other ways in order not to compete with other herbivores: He conquered a new area: Aquatic vegetation, which required a new feeding organ : THE MOOSE NOSE as known today WAS BORN!
The broad-fronted moose came from Eurasia to North-America 10,000 years ago over the Bering land bridge and took - with the retreat of the last great glaciers - the habitat of the stag moose, who died out there 10,500 years ago. The moose nose went international. This shows the close relationship between Eurasian and North-American moose: both are new-world deer. The source of today's moose populations seems to be the region of Yakutia / Manchuria in eastern Asia - the oldest modern moose has been identified by genetic testing as having come from there.
Thanks to my friend Jim Kotowski for our mutual exchange between friends of moose and his "native language support" for this section.