Jaekelopterus rhenaniae

Jaekelopterus rhenaniae (Waterston, 1964)
Arthropoda
Cherlicerata
Merostomata
Eurypterida (Sea Scorpions)
Pterygotioidea
Pterygotidae

Middle Devonian
Germany

Length: 2.6 m (3.6 m if chelicerae (pincers) extended)

One of the largest arthropods of all time, she prefers to hunt in freshwater rather than the saltier homes of her ancestors.

Saturday, March 28th, 2015

Velociraptor mongoliensis

Velociraptor mongoliensis (Osborn, 1924)
Dinosauria
Saurischia
Theropoda
Tetanurae
Coelurosauria
Maniraptora
Paraves
Dromaeosauridae
Velociraptorinae

Late Cretaceous
Mongolia, China

Length: 2.07 m

While you could almost certainly train her to open doors, her relatively short legs mean that motorcycle rides probably aren't going to work too well. Her large eyes allow her to see well at night. Clever girl.

Saturday, March 21st, 2015

Majungasaurus crenatissimus

Majungasaurus crenatissimus (Lavocat, 1955)
Dinosauria
Saurischia
Theropoda
Ceratosauria
Abelisauroidea
Abelisauridae
Majungasaurinae

Late Cretaceous
Madagascar

Length: 8 m

When she's not busy sleeping, Majungasaurus dined on sauropods such as Rapetosaurus and, occasionally, other Majungasaurus.

March 2015

Tylosaurus pembinensis

Tylosaurus pembinensis (Marsh, 1872)

Sauropsida

Diapsida

Lepidosauria

Squamata

Mosasauroidea

Mosasauridae

Tylosaurinae

Late Cretaceous

Central / Western United States

Length: 15 m

More than a century after Cope and Marsh first dug up fossils of this giant squamate, our view of her has changed drastically. We now know that she possessed an asymmetrical tail fluke, was countershaded, lacked a dorsal crest, and is most likely more closely related to monitor lizards than she is to snakes.

March 2015

Carcharodontosaurus iguidensis

Carcharodontosaurus iguidensis (Brusatte & Sereno, 2007)
Dinosauria
Saurischia
Theropoda
Tetanurae
Carnosauria
Allosauroidea
Carcharodontosauridae

Early - Late Cretaceous
North Africa

Length: 10 - 13 m

One of the largest carnivores to ever walk the Earth, she has evolved serrated blade-like teeth, adapted to slicing through flesh with ease.

March 2015

Basilosaurus isis

Basilosaurus isis (Andrews, 1904)
Mammalia
Theria
Eutheria
Laurasiatheria
Artiodactyla
Whippomorpha
Cetacea
Basilosauridae

Late Eocene
Egypt and Jordan

12 - 20 m

This ancient predatory whale's strange name comes from the fact that its bones were initially thought to belong to some sort of enormous non-avian sauropsid (reptile for those less cladistically inclined).

February 28th, 2015

UPDATE: Shortly after I published this post, a new paper came out showing that Basilosaurus had the strongest bite force of any known mammal (over 3,600 pounds at its upper third premolar), enough to break open the skulls of juvenile Dorudon, another (smaller) ancient whale.
Source: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118380