It's a chilly #MarineLifeMonday, so it seems appropriate to recognize that #winter here in the Great #Northwest has its perks. On #PugetSound, those perks include #seabirds, like these #grebes and #gulls, which #flock to the protected, food-rich #waters of the #SalishSea. You don't even have to find a remote #shoreline to appreciate these #birds; these were spotted from the #fishing #pier in #Edmonds, just south of a particularly busy #ferry landing in a large #Seattle suburb.

#FossilAdventCalendar Day 19

It's appropriate that this #MarineLifeMonday our journey #north reaches the shores of #Hudson'sBay at #Churchill, #Manitoba 🇨🇦. It's here that the largest complete #trilobite #fossil ever found was uncovered from #Ordovician rocks. If you want to see the more than two foot long Isotelus rex in person, head to #Winnipeg's #ManitobaMuseum, where it's displayed in all its splendor.

#FossilAdventCalendar Day 12
#MarineLifeMonday

#BritishColumbia's 🇨🇦 #BurgessShale is one of our planet's most important important (and beautiful) #fossil sites. Sitting high in #BC's #RockyMountains, it's a window into the early evolution of #animals. Among its weird wonders is Hallucigenia (seen here in fossil and sculpture form at the #RoyalOntarioMuseum), a distant relative of #arthropods so unlike anything alive today that for years it was reconstructed upside down and backwards.

#FossilAdventCalendar Day 5
#MarineLifeMonday

Most #fish species alive today, from #salmon to #guppies, belong to a single group. In the #Devonian, though, many lineages were abundant. #Quebec's 🇨🇦 #ParcNationalDeMiguasha provides a glimpse of this #biodiversity, which includes #lungfish such as Scaumenacia curta, shown here in the #RoyalOntarioMuseum. Their lobed fins contain many of the same #bones as our arms, evidence that lungfish are much more closely related to us than to most other fish.

It's back to the #RockyIntertidal of #Washington's #SanJuanIslands this #MarineLifeMonday, this time to visit an odd #seaweed group. Coralline red #algae are distant relatives of plants, but they're named because they look like some types of #coral. In fact, this similarity is more than skin-deep. Just as coral animals often encase themselves in calcium #carbonate shells, these algae line their cell walls with the same #mineral, making them much more rigid than other #seaweeds.

@alxsim This is an excellent idea! The big one I would add would be #FossilFriday. I've also been trying out #TerrestrialTuesday to complement #MarineLifeMonday, but I may be the only person on the whole Internet to have actually used that hashtag...

Folks, could we start listing the daily topical hashtags and hashtags dedicated to highlighting diversity that are of interest for this server below this post?

Help us remember what was used on Twitter

I'll start with some:
- #MarineLifeMonday
- #MothMonday
- #DiversityInSTEM
- #WomenInSTEM

I'm featuring an ecosystem rather than an organism this #MarineLifeMonday. Lasting for only a short time but providing a bonanza for #DeepSea life, a #whale fall occurs when a whale dies and sinks to the #ocean floor. The carcass provides rare #nutrients for a range of #scavengers, from microscopic bacteria to huge sharks. The whale fall shown here is an artificial one on display at the #MontereyBayAquarium, where spider #crabs, giant #isopods, and jawless #hagfish occupy a #SpermWhale skeleton.

Since #MarineLifeMonday is a thing (and I'm REALLY hoping it catches on here), how about #TerrestrialTuesday to feature your favorite land-living organisms? My offering is Tamiasciurus hudsonicus, a #squirrel known by many common names. While many #squirrels feed on seeds and nuts, this species prefers the cones of #conifers and is often found in places with more of these evergreen #trees. This one was spotted in #Gatineau, #Quebec at the far southern edge of #Canada's great northern #forests.

On other sites, #NOAA uses #MarineLifeMonday to share the #undersea wonders of their #NationalMarineSanctuaries, but it's a great opportunity to more broadly celebrate #oceanic life past and present and I'm hoping it catches on here! With that in mind, please appreciate this leather star (Dermasterias imbricata), an important #predator of other #intertidal #invertebrates along the West Coast. This one was spotted at a very low tide in Washington's #SanJuanIslands.