Overstrike on a Ptolemy II bronze?

[Andrew McCabe]

Below a new coin, it's a Republican quadrans of a type not listed in Crawford RRC, 42/4 without the corn-ear; Crawford in RRC table XVIII lists such a variety overstruck on a bronze of Hieron II with horseman as this type: http://www.acsearch.info/record.html?id=692756
but I think my coin is overstruck on Ptolemy II, Zeus Eagle on thunderbolt, as this: http://www.acsearch.info/record.html?id=658153

See below my comparison pic. I'm pretty certain I can see Zeus' curls on the reverse at 7pm, i.e. about upright; that doesn't fit the Hieron II. On the obverse I can see feathers across the cheek and various other bumps, e.g. at the neck line. The feathers help convince me it is Ptolemy II, but I'm not at all sure I've the orientation correct. The cheek feathers seem to point in two directions, some pointing towards 1pm, others towards 2pm. I've oriented the Ptolemaic coin as best I can guess but I might be wrong. Am I right on the undertype, and if so, its orientation?

[Molinari]

Without knowing the roman type it is tough to say.  Is there a clear example of the first coin (i.e. no evidence of overstrike) you could post so we know which parts of the design are supposed to be there and which aren't?

Nick

[Andrew McCabe]

Without knowing the roman type it is tough to say.  Is there a clear example of the first coin you could post so we know which parts of the design are supposed to be there and which aren't?

Nick

I post pics of a couple of other examples in my collection below, although all suffer from being overstrikes as are probably 100% of these coins. Note that my new coin does not have the corn-ear present on the first two coins below, but they are all about the same weight. Below these I post a pic of the Roman type (without cornear) that these Sicilian-Roman coins took their designs from; it's a far larger coin (weighing about 40 grams compared to about 15 grams for the three examples I show), but you can see the design elements. The relative sizes are about right.

[Molinari]

I think you're right about it being a Ptolemaic coin but I don't know if you could determine the exact issue, since they are all so similar.  The lines on the cheek to me are the best indication, and combined with the hair, which otherwise could be anyone's, I think your attribution is correct. Is there other evidence of that specific type circulating in the area, etc.?

Nick

[Andrew McCabe]

I think you're right about it being a Ptolemaic coin but I don't know if you could determine the exact issue, since they are all so similar.  The lines on the cheek to me are the best indication, and combined with the hair, which otherwise could be anyone's, I think your attribution is correct. Is there other evidence of that specific type circulating in the area, etc.?

Nick

Crawford lists one overstrike on a quadrans with corn-ear (i.e. the main type, not this variety) on this Ptolemaic type; he lists very many overstrikes on the Hieron II types. So an overstrike on Ptolemy II is known, in a Sicilian context, but just on one coin. It's far rarer than overstrikes on native Sicilian coins, but is known.

[John Anthony]

I've blurred my vision trying to discern various Ptolemaic undertypes on Nabataean issues, and yours is the kind coin that makes me wish for just a little more of the host coin's details. The best I can ever do with a coin like this is propose a range of undertypes. I see no issues with your assessment, but are there other Ptolemaic types that could render the same features?

[Andrew McCabe]

I see no issues with your assessment, but are there other Ptolemaic types that could render the same features?

There might well be. I suggested this type, Ptolemy II, because the date is about right to be overstruck in the early second Punic war, and because there is one precedent of that type being used as host. Best guess.

Thanks all for straining your eyes and getting blurred vision on this. I have a range of good Punic war overstrikes, thankfully most are rather clearer!

[Pekka K]

This type of Ptolemaic bronze is possibly Sicilian issue.
See link to pdf here: http://www.ptolemybronze.com/

Pekka K

[Andrew McCabe]

This type of Ptolemaic bronze is possibly Sicilian issue.
See link to pdf here: http://www.ptolemybronze.com/

Pekka K

Thanks for the link - the NC 2011 article is interesting. That would be a very neat explanation / solution as to why it is found overstruck by the Romans.

[PtolemAE]

Below a new coin, it's a Republican quadrans of a type not listed in Crawford RRC, 42/4 without the corn-ear; Crawford in RRC table XVIII lists such a variety overstruck on a bronze of Hieron II with horseman as this type: http://www.acsearch.info/record.html?id=692756
but I think my coin is overstruck on Ptolemy II, Zeus Eagle on thunderbolt, as this: http://www.acsearch.info/record.html?id=658153

See below my comparison pic. I'm pretty certain I can see Zeus' curls on the reverse at 7pm, i.e. about upright; that doesn't fit the Hieron II. On the obverse I can see feathers across the cheek and various other bumps, e.g. at the neck line. The feathers help convince me it is Ptolemy II, but I'm not at all sure I've the orientation correct. The cheek feathers seem to point in two directions, some pointing towards 1pm, others towards 2pm. I've oriented the Ptolemaic coin as best I can guess but I might be wrong. Am I right on the undertype, and if so, its orientation?

If your coin is 17.05gm then the weight is correct for a Ptolemaic Sicilian coin (SV610, as illustrated in your post).  Note that SV610 *is* a 'native Sicilian' coin - it's a Ptolemaic coin, but produced by a Ptolemaic mint on Sicily.

Check the apparent orientation of undertype because the SV610 is almost 100% certain to be a 12h (a few are 1h or 11h) die axis.  If your undertype appears to be well off the 12h die axis then it is still possible it's overstruck on a 'Ptolemaic' type but in that case it would have to be one of Hieron II's imitations of Sv610.  Those are also 'native Sicilian' but Hieron's imitative types follow the usual Sicilian practice of being struck on random die axes.   In addition you can try to discern whether the reverse border of the undertype is a solid 'circle' or a circle of dots.  Perhaps knowing that all Sv610 have 12h die axis will help you orient the remnants of the undertype.

Please post the image in Crawford of the 'other known' overstrike of this kind of coin on a Ptolemaic undertype and please give its size and weight.

PtolemAE

[PtolemAE]

Below a new coin, it's a Republican quadrans of a type not listed in Crawford RRC, 42/4 without the corn-ear; Crawford in RRC table XVIII lists such a variety overstruck on a bronze of Hieron II with horseman as this type: http://www.acsearch.info/record.html?id=692756
but I think my coin is overstruck on Ptolemy II, Zeus Eagle on thunderbolt, as this: http://www.acsearch.info/record.html?id=658153

See below my comparison pic. I'm pretty certain I can see Zeus' curls on the reverse at 7pm, i.e. about upright; that doesn't fit the Hieron II. On the obverse I can see feathers across the cheek and various other bumps, e.g. at the neck line. The feathers help convince me it is Ptolemy II, but I'm not at all sure I've the orientation correct. The cheek feathers seem to point in two directions, some pointing towards 1pm, others towards 2pm. I've oriented the Ptolemaic coin as best I can guess but I might be wrong. Am I right on the undertype, and if so, its orientation?

Hi Andrew

I took the reverse of your coin and rotated it 180Deg and I now see that it appears to be the obverse of a Hieron II portrait/horseman type.  You can see the top of Hieron's portrait and curly hair near the top of this view and the crown of his head at about 1-2h.  Seems the back of the diadem also visible near 3h, possibly a laurel leaf.  On this portrait type the portrait faces left and that is how this pic is oriented to show it.

The weight of the Hieron coin is the same as a Ptolemaic Sicilian coin so the 17.05 gram weight of your coin is fully consistent with either.  In this case the apparent clear visibility of the top of the portrait head of the undertype makes it look like the overstrike is on a Hieron portrait/horseman coin rather than a Ptolemaic Sicilian coin.  During the 2nd Punic war there would likely have been a lot more Hieron/horseman coins around to for 'flan material' than older Ptolemaic Sicilian coins (made briefly ca. 264BC).

You might examine the other side of your coin (your obverse) to see if you can find the horseman with lance in the undertype - it could be at any rotational orientation (Hieron II coins have random die axes).

PtolemAE

Added to post later -

There's now a picture of the relevant type of Hieron II portrait coin added to this post.  This happens to be the type with laurel wreath (the other variation has a diadem instead). 

PtolemAE

[djmacdo]

The coin is certainly overstruck, but the hair of the host coin just does not look like the Ptolemaic hair to me.  This seems to be in tight ringlets, while the Ptolemaic has wilder, broader locks.

[Andrew McCabe]

Hi Ptolemae

The ringlets indeed look like Hieron II (also the view of djmacdo). I've not yet been able to figure out the obverse marks on the cheeks which looked to me like feathers, but perhaps it is the right arm and body of the horseman, as the cheek marks are at a similar angle to the arm=body angle, and the striations on the horseman's body may have looked like feathers when overstruck. I'll have a closer look at the actual coin when it's next at home (not today). For those new to the thread, my coin, and a link to the Hieron II type are in the first post above: https://www.forumancientcoins.com/board/index.php?topic=94653.msg587003#msg587003

The same type overstruck on Ptolemy II, Svoronos 610, is listed in Crawford's extensive table of overstrikes, which are not illustrated, and references Hersh 10. That would be coin 10 in Charles Hersh, Overstrikes as evidence for the history of Roman Republican coinage, in NC 1953. I don't have NC 1953 to hand; Crawford and a later article, Charles Hersh, Some additional Roman Republican overstrikes, in ANS Museum Notes 1987, in combination with the Hersh bequest to the BM which are all illustrated, generally take the place of NC 1953, but this seems to have been one of those coins not in the Hersh bequest and not later illustrated.

Overstrikes are fun and Punic war ones especially interesting as there's a wide but not unlimited range of possibilities that includes much of the Mediterranean. Thanks for the help on this!

Andrew

[PtolemAE]

Hi Ptolemae

The ringlets indeed look like Hieron II (also the view of djmacdo). I've not yet been able to figure out the obverse marks on the cheeks which looked to me like feathers, but perhaps it is the right arm and body of the horseman, as the cheek marks are at a similar angle to the arm=body angle, and the striations on the horseman's body may have looked like feathers when overstruck. I'll have a closer look at the actual coin when it's next at home (not today). For those new to the thread, my coin, and a link to the Hieron II type are in the first post above: https://www.forumancientcoins.com/board/index.php?topic=94653.msg587003#msg587003

The same type overstruck on Ptolemy II, Svoronos 610, is listed in Crawford's extensive table of overstrikes, which are not illustrated, and references Hersh 10. That would be coin 10 in Charles Hersh, Overstrikes as evidence for the history of Roman Republican coinage, in NC 1953. I don't have NC 1953 to hand; Crawford and a later article, Charles Hersh, Some additional Roman Republican overstrikes, in ANS Museum Notes 1987, in combination with the Hersh bequest to the BM which are all illustrated, generally take the place of NC 1953, but this seems to have been one of those coins not in the Hersh bequest and not later illustrated.

Overstrikes are fun and Punic war ones especially interesting as there's a wide but not unlimited range of possibilities that includes much of the Mediterranean. Thanks for the help on this!

Andrew

Your coin seems to be shouting "I was Hieron before Rome reused me as a flan".

Thanks for the Crawford ref.  I've seen written references to the Ptolemaic Sicilian coins being overstruck by Hieron II portrait types as well as at least this one ref. to an overstrike by Roman Republican dies.  I'd like to actually see one some day and confirm it is either a true Ptolemaic Sicilian issue (Sv 610) or one of the related imitations produced by Hieron II.  Until our paper on them there wasn't much of a distinction made between the two categories.

Mac (djmacdo) here is *the expert* on overstrikes and has provide a great deal of helpful information and insights on the subject.  You'll enjoy his excellent book on the subject, published by Whitman. 

There are interesting Ptolemaic bronze coins of 3rd C. BC overstruck by 'proto-Nabataean' types that used to be quite rare by seem now more widely available.  Occasionally the specific Ptolemaic undertype can be determined and most seem to be tied to Ptolemy II and III.

Also some fairly scarce Ptolemaic bronzes are overstruck by other Ptolemaic (or possibly 'barbaric' Ptolemaic) designs ca. early 2nd C. BC.  Those specific undertypes are pretty hard to make out, somewhat worn, but it's clear they are present.

PtolemAE

[Andrew McCabe]

Mac (djmacdo) here is *the expert* on overstrikes and has provide a great deal of helpful information and insights on the subject.  You'll enjoy his excellent book on the subject, published by Whitman.  

Yes I've got that book! Curiously, rather than buying from a numismatic bookseller, I think I picked it off a shelf of a Borders in Houston some years back, where it was being sold alongside other Whitman guides.

I've quite an inventory of overstrikes in my collection, some unpublished. I deliberately choose (Roman) coins where the (Greek or Roman) undertype is clearly visible, and hopefully where both under and overstrike are in nice condition. Some crop up repetitively, but still are interesting if especially clear, such as the coin below, a 50/50 overstrike where the undertype is just as visible as the overtype. The overtype, if one can't see it, is Hercules / Bull and corn-ear Roman; the Syracusan undertype is shown on the lower pic.

[PtolemAE]

Mac (djmacdo) here is *the expert* on overstrikes and has provide a great deal of helpful information and insights on the subject.  You'll enjoy his excellent book on the subject, published by Whitman.  

Yes I've got that book! Curiously, rather than buying from a numismatic bookseller, I think I picked it off a shelf of a Borders in Houston some years back, where it was being sold alongside other Whitman guides.

I've quite an inventory of overstrikes in my collection, some unpublished. I deliberately choose (Roman) coins where the (Greek or Roman) undertype is clearly visible, and hopefully where both under and overstrike are in nice condition. Some crop up repetitively, but still are interesting if especially clear, such as the coin below, a 50/50 overstrike where the undertype is just as visible as the overtype. The overtype, if one can't see it, is Hercules / Bull and corn-ear Roman; the Syracusan undertype is shown on the lower pic.

Hope you can get all your pix and examples to djmacdo for the next edition of his book.

On this example it's important again to know the weight of your overstrike.  The undertype appears to be a Hieron 'trident' type but it's not a certainty as similar coins were struck under roman occupation of syracuse after 212BC.  I can't see the word that is under the trident base here that would clinch one type or the other.  

Also if it is indeed a Hieron Poseidon/trident undertype there were two sizes of those.  The one you've illustrated as the undertype below is the larger type with mean weight about 8.5 grams (it is highly likely that type represents 1/2 of a portrait/horseman coin's value, the mean weight ratio being almost perfectly 1:2).  The smaller ones are closer to mean of about 6 grams and have a less refined style of Poseidon portrait.  There are also minor differences in how the name 'IERONOS' is written out on the two sizes.

IOW if your overstrike does indeed represent the undertype you've illustrated then I would expect it weighs 7.5 - 9.5 grams.  If it's much lighter then questions arise as to the exact undertype.  The Hieron Poseidon/trident coin you've used as an illustration may or may not actually be the undertype.

The importance of giving coin weights with all coin photos/illustrations cannot be overstated.

PtolemAE

[Andrew McCabe]

Hope you can get all your pix and examples to djmacdo for the next edition of his book.

On this example it's important again to know the weight of your overstrike.  The undertype appears to be a Hieron 'trident' type but it's not a certainty as similar coins were struck under roman occupation of syracuse after 212BC.  ...

Here's a link to my overstrikes in my collection, with weight data; for coins still in my collection (I do turnover my coins) die axis also available on request.

http://www.flickr.com/search/?q=overstrike&ss=2&ct=6&mt=all&w=36294246%40N03&adv=1

I could have posted weights before, but I guess I was in a 'Roman' collector mind and assumed that the readers would recognise the Roman type and its typical weight! In the case of the trident coins, the Roman quadrans typically weighs 8 grams. In the case of the horseman coins the Roman quadrans, with the same design, typically weigh 16 grams. Though djmacdo's book dealt with Greek overstrikes it would be nice to include some Roman on Roman overstrikes if possible, that they are part of the same conflict as the many Roman on Greek types. It's all part of the same economic picture.

Its also worth searching the Hersh bequest overstrikes in the British Museum, they are almost all second Punic war Roman on Greek types; BM pics can be used in print books and articles, but not on the web, without seeking the BMs explicit permission so long as they are properly credited. I can't give a link to the BM overstrikes as their web addresses are about a paragraph long, but go to my home page, http://andrewmccabe.ancients.info then scroll down a half page and you will see a search box for British Museum Coins, put Overstrike in the search box and you get 56 results.

I have behind my firewall many more duplicate overstrike pics of similar types but where the pics may not be my copyright. But my own collection is reasonably represented with usually clear overstrikes i.e. with the undertype visible as is my preference, as I see little point in buying a coin type known to be an overstrike without being able to see what it was struck on!
Andrew

[PtolemAE]

Hope you can get all your pix and examples to djmacdo for the next edition of his book.

On this example it's important again to know the weight of your overstrike.  The undertype appears to be a Hieron 'trident' type but it's not a certainty as similar coins were struck under roman occupation of syracuse after 212BC.  ...

Here's a link to my overstrikes in my collection, with weight data; for coins still in my collection (I do turnover my coins) die axis also available on request.

http://www.flickr.com/search/?q=overstrike&ss=2&ct=6&mt=all&w=36294246%40N03&adv=1

I could have posted weights before, but I guess I was in a 'Roman' collector mind and assumed that the readers would recognise the Roman type and its typical weight! In the case of the trident coins, the Roman quadrans typically weighs 8 grams. In the case of the horseman coins the Roman quadrans, with the same design, typically weigh 16 grams. Though djmacdo's book dealt with Greek overstrikes it would be nice to include some Roman on Roman overstrikes if possible, that they are part of the same conflict as the many Roman on Greek types. It's all part of the same economic picture.

Its also worth searching the Hersh bequest overstrikes in the British Museum, they are almost all second Punic war Roman on Greek types; BM pics can be used in print books and articles, but not on the web, without seeking the BMs explicit permission so long as they are properly credited. I can't give a link to the BM overstrikes as their web addresses are about a paragraph long, but go to my home page, http://andrewmccabe.ancients.info then scroll down a half page and you will see a search box for British Museum Coins, put Overstrike in the search box and you get 56 results.

I have behind my firewall many more duplicate overstrike pics of similar types but where the pics may not be my copyright. But my own collection is reasonably represented with usually clear overstrikes i.e. with the undertype visible as is my preference, as I see little point in buying a coin type known to be an overstrike without being able to see what it was struck on!
Andrew

Thank you, Andrew - what I lack in knowledge of Roman coins could fill libraries.  The exact weight of this particular specimen (rather than 'typical weight') would be helpful.

The mean weight of Hieron horseman coins is 17.1-17.2 grams, not 16.  The data are based on hundreds of specimens and there is unlikely to be any serious doubt about the accuracy of that weight value, but you can quickly run the calculations on the specimens in SNG ANS and get about those same numbers for their collection of about 80 pieces.  Our paper in NC (2011) on the 'Sicilian Ptolemaic' bronzes showed that their weights are statistically identical to the Hieron horseman coins as well (as are Hieron's 'imitation' Ptolemaic issues).  Many more data have been gathered on all of those types since the 2011 paper was published and the numbers and comparisons held up.  17.2 turns out to be a *very* interesting number and a paper currently in press (AJN 2013) has more to say about it that was not apparent when the 2011 paper was written.  I was quite surprised to discover an extended meaning of 17.2 grams.

If the 'typical' weight of the roman types overstruck on Hieron horseman coins is only 16 grams then either the flans were reduced when overstruck or no one has sytematically analyzed a large sample of them to get statistically persuasive weight data so that the '16' value underestimates the true value by about 1.1 - 1.2 grams.  If, however, the roman republic coins of this type, in general (irrespective of being overstruck on Hieron horseman coins), actually average out to 17.1-17.2 grams (rather than 16) then that itself is an important thing to know and may impart even additional importance to that value.

Likewise it will be helpful to know if the 'half' types (as here shown overstruck on a trident-reverse type) actually weigh about 8.5-8.6 (vs. 'typically 8') that is also important for the same reason (that the Romans either did or did not adopt the extant bronze weight standard of Sicilian bronze coins of 3rd C. BC Syracuse).

PtolemAE

[Andrew McCabe]

The weight of this coin is 17.05 grams, which is exactly as per your data.

The weight of the coin type i.e. the overstrike average 15-16 grams. My other examples weigh 14.88 grams and 14.00 grams. Of course they are also overstruck on other coins of both known and unknown types, and there may be some fresh made blanks. The weight range for the type ranges from 12 to 18 grams, with essentially the same dies used ay the extremes. Oddly sometimes mid weight coins of 15 grams have larger dies which leads me to suspect that 15 grams was the target weight and fresh blanks were made at fhat weight but when booty was captured any coin that was a bit heavier or lighter was used as a blank. Its worth clicking through my collection overstrikes at the link given previously to see fge range of weights and under types, where known.

Knowledge that the undertypes occur in very narrow weight ranges may help in future analysis of the series and of other Punic war overtypes. It may allow us to reverse analyse for undertypes ie to bracket groups of coins as likely being overstruck on x, y or z. There's about 50 common Roman overstrike types in the second Punic war, struck on a much smaller variety of host flans. This would make an interesting article!

[PtolemAE]

The weight of this coin is 17.05 grams, which is exactly as per your data.

The weight of the coin type i.e. the overstrike average 15-16 grams. My other examples weigh 14.88 grams and 14.00 grams. Of course they are also overstruck on other coins of both known and unknown types, and there may be some fresh made blanks. The weight range for the type ranges from 12 to 18 grams, with essentially the same dies used ay the extremes. Oddly sometimes mid weight coins of 15 grams have larger dies which leads me to suspect that 15 grams was the target weight and fresh blanks were made at fhat weight but when booty was captured any coin that was a bit heavier or lighter was used as a blank. Its worth clicking through my collection overstrikes at the link given previously to see fge range of weights and under types, where known.

Knowledge that the undertypes occur in very narrow weight ranges may help in future analysis of the series and of other Punic war overtypes. It may allow us to reverse analyse for undertypes ie to bracket groups of coins as likely being overstruck on x, y or z. There's about 50 common Roman overstrike types in the second Punic war, struck on a much smaller variety of host flans. This would make an interesting article!

Thanks for the additional details. 

The weight of the 2nd overstrike coin you showed (the one with the trident undertype) remains unknown so please let us know that when you can.

Your first coin's 17.05gm weight is as expected.  The Hieron (and related Ptolemaic) bronze coins do vary a bit but this weight is certainly not surprising. 

Some detailed analysis of other roman overstrikes might uncover the source of unidentifiable undertypes as data do exist for other Sicilian coins that could be in the 12 - 18 gram sizes, perhaps not necessarily the Hieron undertypes.  It could well be that various 'booty' coins were overstruck irrespective of any strict weight for a particular roman type and that the roman coin types were not well-controlled for weight in any case. 

And yes, indeed, a metrological study comparing roman punic war bronzes to known Sicilian coin types would make an interesting read.  There are fairly decent weight data for a number of pre-existing Sicilian types to the overstrike weight might tell which undertype it is irrespective of the undertype's design visibility.  It could probably address the question of whether the roman coinage had any meaningful relationship to the pre-existing coinage of that area.

PtolemAE

[Andrew McCabe]

The weight of the 2nd overstrike coin you showed (the one with the trident undertype) remains unknown so please let us know that when you can.

It's not "unknown": I said twice before that the data for each coin is in the linked list of pictures! Have a look, and click on any coin of interest, you'll find its data, including weight, catalogue references, likely undertypes etc:
http://www.flickr.com/search/?q=overstrike&ss=2&ct=6&mt=all&w=36294246%40N03&adv=1

Here is what you get when you click on this particular coin (the trident overstrike)
http://www.flickr.com/photos/ahala_rome/8480646085/
i.e. the weight is 5.67 grams

You'll find several other coins overstruck on the same trident type among my overstrikes, this coin is not the only one I have with that particular Syracusan undertype. As noted before, I've also many more Roman-on-Greek overstrike pics, dozens anyway, but some are from  private collections so not all are displayed via the link above

[PtolemAE]

The weight of the 2nd overstrike coin you showed (the one with the trident undertype) remains unknown so please let us know that when you can.

It's not "unknown": I said twice before that the data for each coin is in the linked list of pictures! Have a look, and click on any coin of interest, you'll find its data, including weight, catalogue references, likely undertypes etc:
http://www.flickr.com/search/?q=overstrike&ss=2&ct=6&mt=all&w=36294246%40N03&adv=1

Here is what you get when you click on this particular coin (the trident overstrike)
http://www.flickr.com/photos/ahala_rome/8480646085/
i.e. the weight is 5.67 grams

You'll find several other coins overstruck on the same trident type among my overstrikes, this coin is not the only one I have with that particular Syracusan undertype. As noted before, I've also many more Roman-on-Greek overstrike pics, dozens anyway, but some are from  private collections so not all are displayed via the link above

Thanks, Andrew -

Not much free time right now to go searching for the weight value on another site.

5.67 grams means it is almost certainly *not* an example of the type you used for illustrating its undertype.  The undertype is either the (related) smaller size of Poseidon/Trident coin of Hieron II or the later 'Syrakosion' variety produced in 'Syracuse under Roman Rule' after ca. 212.  In either case it would be likely a later-issue coin that the ca. 8.6 gram (mean wt) Poseidon/Trident coin used in your illustration.  The reason for the 2nd issue of lighter Poseidon/trident coins by Hieron II (mean weight 6.6 grams) is not clear.  Their (lower) weights are not easily linked to other coin types.

PtolemAE