Whether or not the monument at Amphipolis turns out to be a tomb or a heroon, and whether it was a simple monument or one of several, of course will only become clear as work progresses.
To "purr with pleasure" is an English expression to show contentment, and one could argue that every find Katerina Peristeri makes at Amphipolis makes us "purr with pleasure" ...
as discovered in 1858).
The Cnidus tomb is interesting for the way it compares and contrasts with the lion and base element at Amphipolis. Most people would point out the dissimilar pose of the lions and move on. Archaeology is as much an art as a science, where some facts can be verified through scientific tests, but others need to be thought out through comparanda to come to the balance of probability.
The key point is that the architecture of the base, with Doric half-columns and a shield in relief between them is similar to the base of the Amphipolis Lion as reconstructed by Oscar Broneer.
Lifting a colossal lion onto a monument is hard to engineer at the best of times, and even harder when there is a large mound in the way. The two architects came up with different solutions; the Amphipolis lion was carved over a series of blocks which could be lifted into place one by one; the belly of the Cnidus lion is hollowed out so that it weighed less.
The colossal lions closest in pose to the Lion of Amphipolis are the Chaeronea Lion, almost certainly linked to Philip II's victory there, and the Piraeus Lion, of less certain date and context as it was taken by Morosini to Venice.
Another English expression concerns people talking out of their arses (American spelling: ass) or behaving like an ass, which is what some silly people have done about Dr Peristeri and her brilliant work at Amphipolis. Although an ass is closer to a donkey, this lion attacking a horse makes a good illustration (all photos from Getty).
The statue was 'excavated' or more likely 'dredged' from the riverbank by the ancient Circus Maximus, so we can guess that in the Roman period it decorated the circus, a sculptural depiction of the real animal fights that sometimes took place there.
Although we know the statue was in ancient Rome, it was neither a Roman work nor made to decorate the Circus Maximus. Instead, like many other sculptures in Rome, it was probably a Greek original brought 'home' by a conquering Roman general to celebrate his victories abroad.
The condition of the sculpture is not ideal for stylistic dating, but most experts agree that it comes roughly from the time of Alexander the Great. A hole in the back of the lion would once have held a spear, showing that this image was part of a hunting scene whose human participants have been lost over the centuries.
Lion hunts were the preserve of royalty, and Persian-style hunting parks were introduced to Macedonia by Philip II - as shown on the frieze of Tomb II at Vergina. A Persian-style Lion Hunt with a lion attacking a horse was shown on the so-called Alexander Sarcophagus from Sidon (here; it was probably made for a local ruler, and depicts Alexander but was not made for him). The Alexander Sarcophagus imitated the Mausoleum of Halicarnassus, where a lion hunt was shown, and the Mausoleum in turn was influenced by the sarcophagus carved for his father Hecatomnus, which also showed a lion hunt. It was a symbol of royal power used by the Hecatomnids in much of their art, and which entered Macedonian art when Philip II hired the same artists they had previously employed.
All those lion hunts are quite different from the Lion Attacking a Horse found in Rome. They merely show how important a lion hunt was as an expression of royal power, just as Augustus using a seal with a Sphinx and an image of Alexander the Great was an indication of his inspiration at the time he was building his Mausoleum in Rome.
We cannot be sure for where the Rome lion was originally created, but we can be sure it was considered an important work as it was also copied in Antiquity, for example in this circa AD 150 mosaic now in the Getty. In tombs size was important, so the bigger the tomb the more important the person for whom it was intended. And with art, the more it was copied the more likely it is that the original was important.
One point worth making is that although the Roman sculpture is restored as a horse, in this mosaic it looks more like a donkey or an ass.
It is a pity that the original location of the Getty mosaic is unknown, but that is the difference between excavations and 'digging' to fuel the art market. The Cnidus Lion almost purrs with pleasure, as I do over Dr Peristeri's excavations at Amphipolis. It'll leave it up to you guys to decide who I think is behaving like an ass.
There is an art to interpreting archaeological finds, and some people lack it.